Convert FabricUIManager from Java to Kotlin

Summary:
This diff converts `FabricUIManager.java` to Kotlin as part of the ongoing React Native Android Java-to-Kotlin migration effort.

Key changes:
- Converted the class from Java to Kotlin with idiomatic patterns
- Removed Hungarian notation from all private fields (e.g. `mBinding` -> `uiManagerBinding`, `mDestroyed` -> `destroyed`)
- Static fields (`TAG`, `IS_DEVELOPMENT_ENVIRONMENT`) and static initializer moved to `companion object` with `JvmField` for binary compatibility
- `eventDispatcher` and `performanceCounters` implemented as `override val` properties matching Kotlin interface definitions
- Package-private methods (`setBinding`, `createDispatchCommandMountItemForInterop`) mapped to `internal`
- All `!!` operator usages replaced with `checkNotNull`/`requireNotNull` for safer null handling
- Nullable `commandArgs` passed through via unchecked cast to preserve original Java null-pass-through behavior
- `OptIn(UnstableReactNativeAPI::class)` added at class level

Supporting changes required by the migration:
- `DevToolsReactPerfLogger.kt`: `private companion object` changed to `internal companion object` since Kotlin enforces companion visibility that Java did not
- `SynchronousMountItem.kt`: Import path updated to use `FabricUIManager.Companion.IS_DEVELOPMENT_ENVIRONMENT`
- `PreparedLayout.kt`: Changed from `internal` to `public` because `FabricUIManager` public JNI-facing methods return/accept this type
- `ReactAndroid.api`: Regenerated to reflect the updated API surface

Changelog: [Internal]

Differential Revision: D107865206

Author: cortinico

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -2223,57 +2223,61 @@ public final class com/facebook/react/fabric/DevToolsReactPerfLogger$FabricCommi
 }
 
 public class com/facebook/react/fabric/FabricUIManager : com/facebook/react/bridge/LifecycleEventListener, com/facebook/react/bridge/UIManager, com/facebook/react/fabric/interop/UIBlockViewResolver, com/facebook/react/uimanager/events/SynchronousEventReceiver {
+	public static final field Companion Lcom/facebook/react/fabric/FabricUIManager$Companion;
 	public static final field IS_DEVELOPMENT_ENVIRONMENT Z
 	public static final field TAG Ljava/lang/String;
 	public field mDevToolsReactPerfLogger Lcom/facebook/react/fabric/DevToolsReactPerfLogger;
 	public fun <init> (Lcom/facebook/react/bridge/ReactApplicationContext;Lcom/facebook/react/uimanager/ViewManagerRegistry;Lcom/facebook/react/uimanager/events/BatchEventDispatchedListener;)V
 	public fun addRootView (Landroid/view/View;Lcom/facebook/react/bridge/WritableMap;)I
-	public fun addUIBlock (Lcom/facebook/react/fabric/interop/UIBlock;)V
+	public final fun addUIBlock (Lcom/facebook/react/fabric/interop/UIBlock;)V
 	public fun addUIManagerEventListener (Lcom/facebook/react/bridge/UIManagerListener;)V
-	public fun attachRootView (Lcom/facebook/react/fabric/SurfaceHandlerBinding;Landroid/view/View;)V
-	public fun clearJSResponder ()V
-	public fun dispatchCommand (IIILcom/facebook/react/bridge/ReadableArray;)V
+	public final fun attachRootView (Lcom/facebook/react/fabric/SurfaceHandlerBinding;Landroid/view/View;)V
+	public final fun clearJSResponder ()V
+	public final fun dispatchCommand (IIILcom/facebook/react/bridge/ReadableArray;)V
 	public fun dispatchCommand (IILcom/facebook/react/bridge/ReadableArray;)V
-	public fun dispatchCommand (IILjava/lang/String;Lcom/facebook/react/bridge/ReadableArray;)V
+	public final fun dispatchCommand (IILjava/lang/String;Lcom/facebook/react/bridge/ReadableArray;)V
 	public fun dispatchCommand (ILjava/lang/String;Lcom/facebook/react/bridge/ReadableArray;)V
-	public fun findNextFocusableElement (III)Ljava/lang/Integer;
-	public fun getColor (I[Ljava/lang/String;)I
+	public final fun findNextFocusableElement (III)Ljava/lang/Integer;
+	public final fun getColor (I[Ljava/lang/String;)I
 	public fun getEventDispatcher ()Lcom/facebook/react/uimanager/events/EventDispatcher;
 	public fun getPerformanceCounters ()Ljava/util/Map;
-	public fun getRelativeAncestorList (II)[I
-	public fun getThemeData (I[F)Z
+	public final fun getRelativeAncestorList (II)[I
+	public final fun getThemeData (I[F)Z
 	public fun initialize ()V
 	public fun invalidate ()V
 	public fun markActiveTouchForTag (II)V
-	public fun measure (ILjava/lang/String;Lcom/facebook/react/bridge/ReadableMap;Lcom/facebook/react/bridge/ReadableMap;Lcom/facebook/react/bridge/ReadableMap;FFFF)J
-	public fun onAllAnimationsComplete ()V
-	public fun onAnimationStarted ()V
+	public final fun measure (ILjava/lang/String;Lcom/facebook/react/bridge/ReadableMap;Lcom/facebook/react/bridge/ReadableMap;Lcom/facebook/react/bridge/ReadableMap;FFFF)J
+	public final fun onAllAnimationsComplete ()V
+	public final fun onAnimationStarted ()V
 	public fun onHostDestroy ()V
 	public fun onHostPause ()V
 	public fun onHostResume ()V
-	public fun onRequestEventBeat ()V
-	public fun prependUIBlock (Lcom/facebook/react/fabric/interop/UIBlock;)V
+	public final fun onRequestEventBeat ()V
+	public final fun prependUIBlock (Lcom/facebook/react/fabric/interop/UIBlock;)V
 	public fun profileNextBatch ()V
 	public fun receiveEvent (IILjava/lang/String;Lcom/facebook/react/bridge/WritableMap;)V
-	public fun receiveEvent (IILjava/lang/String;ZLcom/facebook/react/bridge/WritableMap;I)V
+	public final fun receiveEvent (IILjava/lang/String;ZLcom/facebook/react/bridge/WritableMap;I)V
 	public fun receiveEvent (IILjava/lang/String;ZLcom/facebook/react/bridge/WritableMap;IZ)V
 	public fun receiveEvent (IILjava/lang/String;ZLcom/facebook/react/bridge/WritableMap;IZJ)V
 	public fun receiveEvent (ILjava/lang/String;Lcom/facebook/react/bridge/WritableMap;)V
 	public fun removeUIManagerEventListener (Lcom/facebook/react/bridge/UIManagerListener;)V
 	public fun resolveCustomDirectEventName (Ljava/lang/String;)Ljava/lang/String;
 	public fun resolveView (I)Landroid/view/View;
 	public fun sendAccessibilityEvent (II)V
-	public fun sendAccessibilityEventFromJS (IILjava/lang/String;)V
-	public fun setJSResponder (IIIZ)V
+	public final fun sendAccessibilityEventFromJS (IILjava/lang/String;)V
+	public final fun setJSResponder (IIIZ)V
 	public fun startSurface (Landroid/view/View;Ljava/lang/String;Lcom/facebook/react/bridge/WritableMap;II)I
-	public fun startSurface (Lcom/facebook/react/fabric/SurfaceHandlerBinding;Landroid/content/Context;Landroid/view/View;)V
+	public final fun startSurface (Lcom/facebook/react/fabric/SurfaceHandlerBinding;Landroid/content/Context;Landroid/view/View;)V
 	public fun stopSurface (I)V
-	public fun stopSurface (Lcom/facebook/react/fabric/SurfaceHandlerBinding;)V
+	public final fun stopSurface (Lcom/facebook/react/fabric/SurfaceHandlerBinding;)V
 	public fun sweepActiveTouchForTag (II)V
 	public fun synchronouslyUpdateViewOnUIThread (ILcom/facebook/react/bridge/ReadableMap;)V
 	public fun updateRootLayoutSpecs (IIIII)V
 }
 
+public final class com/facebook/react/fabric/FabricUIManager$Companion {
+}
+
 public final class com/facebook/react/fabric/FabricUIManagerProviderImpl : com/facebook/react/bridge/UIManagerProvider {
 	public fun <init> (Lcom/facebook/react/fabric/ComponentFactory;Lcom/facebook/react/uimanager/ViewManagerRegistry;)V
 	public fun createUIManager (Lcom/facebook/react/bridge/ReactApplicationContext;)Lcom/facebook/react/bridge/UIManager;
@@ -5967,6 +5971,16 @@ public final class com/facebook/react/views/text/DefaultStyleValuesUtil {
 	public static final fun getTextColorSecondary (Landroid/content/Context;)Landroid/content/res/ColorStateList;
 }
 
+public final class com/facebook/react/views/text/PreparedLayout {
+	public fun <init> (Landroid/text/Layout;IF[III)V
+	public final fun getJustificationMode ()I
+	public final fun getLayout ()Landroid/text/Layout;
+	public final fun getMaximumNumberOfLines ()I
+	public final fun getReactTags ()[I
+	public final fun getTextBreakStrategy ()I
+	public final fun getVerticalOffset ()F
+}
+
 public final class com/facebook/react/views/text/ReactFontManager {
 	public static final field Companion Lcom/facebook/react/views/text/ReactFontManager$Companion;
 	public synthetic fun <init> (Lcom/facebook/react/common/assets/ReactFontManager;Lkotlin/jvm/internal/DefaultConstructorMarker;)V

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/fabric/DevToolsReactPerfLogger.kt

@@ -150,7 +150,7 @@ public class DevToolsReactPerfLogger : FabricMarkerListener {
     }
   }
 
-  private companion object {
+  internal companion object {
     @JvmField internal val streamingCommitStats: LongStreamingStats = LongStreamingStats()
 
     @JvmField internal val streamingLayoutStats: LongStreamingStats = LongStreamingStats()