Fix requestConnectionPriority implementation

[aqeel-bmec-co]

🤖 Addresses review comments on Navideck#221

Features/Fixes

• Remove redundant BleCapabilities.supportsConnectionPriorityApi guard in Dart layer — native implementations already return notSupported, consistent with readRssi pattern.
• Add BleConnectionPriority Kotlin enum in UniversalBleHelper.kt mirroring the Dart enum, following the same pattern as BleInputProperty and BleOutputProperty.
• Use explicit when mapping to Android SDK constants (BluetoothGatt.CONNECTION_PRIORITY_*) rather than relying on coincidental index equality.
• Add firstOrNull with ILLEGAL_ARGUMENT early return for unknown priority values.
• Add catch (e: Exception) block to handle SecurityException and other runtime exceptions, consistent with setNotifiable, readValue, and pair.
• Fix enum doc comment — @throws belonged on the calling method, not the enum declaration.
• Remove stale "Check BleCapabilities.supportsConnectionPriorityApi before calling" guidance from API doc and README.

[aqeel-bmec-co]

🤖 PR Review: #2 Fix requestConnectionPriority implementation

Risk: 4/9 — 🟠 Yellow

Dimension	Score	Justification
Impact	2	Non-breaking Android BLE API improvement — affects runtime error handling and enum mapping
Likelihood	2	6 files, moderate complexity in Kotlin logic, no new tests

Reviewer: @raphael-bmec-co — PR author of the original requestConnectionPriority implementation. ✅ Assigned.

Review Focus

File		Review Reason
android/.../UniversalBlePlugin.kt	🔴	Verify firstOrNull + when mapping to Android SDK constants is correct, and catch (e: Exception) doesn't swallow unexpected errors
android/.../UniversalBleHelper.kt	🟠	Confirm BleConnectionPriority enum values (0/1/2) stay in sync with Dart enum indices

Changed Files

File	Type	Notes
android/.../UniversalBlePlugin.kt	source	Enum resolution via firstOrNull, explicit when mapping to SDK constants, added catch (e: Exception)
android/.../UniversalBleHelper.kt	source	New BleConnectionPriority Kotlin enum mirroring Dart enum
lib/src/universal_ble_pigeon/universal_ble_pigeon_channel.dart	source	Removed redundant capability guard, converted to => syntax
lib/src/models/ble_connection_priority.dart	source	Fixed doc comment — removed @throws from enum
lib/src/universal_ble.dart	source	Removed stale capability check guidance from doc comment
README.md	docs	Removed stale "Check BleCapabilities.supportsConnectionPriorityApi" line

[aqeel-bmec-co]

@raphael-bmec-co These changes do affect how the Enum is handled as well as converted. Thus I think we should review/test them

[raphael-bmec-co]

Please update the test up to test as discussed.

[aqeel-bmec-co]

@raphael-bmec-co The test app connects and is able to set the priority. Merging