This PR:

1. Adds proper backup rules for Android 9-11 and data extraction rules for Android 12+
2. Suppresses Android 14+ foreground service lint warnings
3. Configures ABI splits to generate architecture-specific APKs
4. Unifies build output naming for APKs and AABs

Description

Backup Configuration

• Adds backup_rules.xml for Android 9-11 (fullBackupContent) with all domains excluded
• Adds data_extraction_rules.xml for Android 12+ (dataExtractionRules) with empty sections to disable cloud backup and device transfer
• Adds both manifest attributes for complete backward compatibility

Foreground Service

• Suppresses ForegroundServicePermission and ForegroundServicesPolicy lint warnings since the configuration is correct (the warning is informational about Play Console requirements)

Build Outputs

• Enables ABI splits for armeabi-v7a and arm64-v8a architectures
• Generates universal APK as fallback
• Unifies naming format: bitkit-{flavor}-{buildType}-{versionCode}[-abi].apk/aab

Preview

N/A - No UI changes.

QA Notes

1. Verify build outputs

   ./gradlew assembleMainnetRelease
   ls app/build/outputs/apk/mainnet/release/

   Expected files:

   • bitkit-mainnet-release-173-arm64-v8a.apk
   • bitkit-mainnet-release-173-armeabi-v7a.apk
   • bitkit-mainnet-release-173-universal.apk

2. Verify AAB naming

   ./gradlew bundleMainnetRelease
   ls app/build/outputs/bundle/mainnetRelease/

   Expected: bitkit-mainnet-release-173.aab

3. Verify no lint warnings

   • Open AndroidManifest.xml in Android Studio
   • Confirm no warnings on foreground service permission line