Clarify JNI assignability check

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: simonrozsival

src/Mono.Android/Microsoft.Android.Runtime/TrimmableTypeMap.cs

@@ -377,6 +377,9 @@ internal bool TryGetJniNameForManagedType (Type managedType, [NotNullWhen (true)
 			// Verify the Java object is actually assignable to the target Java type
 			// before returning the fallback proxy. Without this, we'd create invalid peers
 			// (e.g., IAppendableInvoker wrapping a java.lang.Integer).
+			//
+			// Note: JNI IsAssignableFrom uses (candidate, targetBase), which is the
+			// reverse of the more familiar managed `targetBase.IsAssignableFrom (candidate)`.
 			if (proxy is null || !self.TryGetJniNameForManagedType (targetType, out var targetJniName)) {
 				return null;
 			}