Add Bluetooth device picker in Settings
- add resource to support device picker
- show different UI accroding to start Intent
- add OPP profile manager
Split BluetoothDevice into BluetoothDevice and BluetoothAdapter.
BluetoothAdapter: Represents the local BT adapter. Operations on the local
adapter (start a scan, etc).
BluetoothDevice: Represents a remote BT device. Operations on remote devices
(pair, connect, etc).