Android: Listen for bluetooth connection state changes

the headset plug/unplug events only capture wired headset events, trigger event on change of bluetooth device.  Currently does not distinguish on type of event but at least adds basic handling  capability for bluetooth devices.

src/android/MusicControls.java

@@ -65,6 +65,9 @@ private void registerBroadcaster(MusicControlsBroadcastReceiver mMessageReceiver
 
 		// Listen for headset plug/unplug
 		context.registerReceiver((BroadcastReceiver)mMessageReceiver, new IntentFilter(Intent.ACTION_HEADSET_PLUG));
+
+		// Listen for bluetooth connection state changes
+		context.registerReceiver((BroadcastReceiver)mMessageReceiver, new IntentFilter(android.bluetooth.BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED));
 	}
 
 	// Register pendingIntent for broacast