Fixed Android connection issues for Android 12 and above.

[champeauxr]

• Updated the Android Google Nearby Connections library to latest version (18.5.0)
• Updated the permissions needed for Android 12 and above.
• Added android:foregroundServiceType and associated permission to NearbyService
• Fixed example build issues with latest Flutter and Android Studio.
• Fixed the method handler in the Kotlin plugin so that it properly return a result for all calls, even when an exception occurs.

Also added a non-breaking change that allows a device name to be specified in the startAdvertisingPeer() call.