[android] Add Android Auto notification support

[derrik-fleming]

Summary

Add support for Android Auto notifications to allow app notifications to appear on the car display interface when connected to compatible Android Auto vehicles.

Problem

Currently, the plugin supports standard Android notification channels and configurations, but there's no way to enable notifications to appear on Android Auto displays. Android Auto requires specific notification extensions and CarAppService integration to display notifications properly on the car interface.

Proposed Solution

• Add showOnAndroidAuto parameter to AndroidNotificationDetails to control Android Auto notification display
• Integrate CarAppExtender and CarNotificationManager for Android Auto compatibility
• Introduce CarAppServiceClassConsumer interface for apps to provide their CarAppService class
• Use CarPendingIntent to enable notifications to launch app on Android Auto
• Maintain backward compatibility - Android Auto support is opt-in per notification
• Fallback to standard notifications if Android Auto is unavailable

Expected Benefits

• Enable notifications on Android Auto car displays (Android 8.0+ / API 26+)
• Full backward compatibility - existing notifications unaffected
• Optional per-notification control via showOnAndroidAuto flag
• Seamless integration with existing notification system
• Graceful degradation when Android Auto is not available or CarAppService not implemented
• Linking support for notification interactions from car display