Change BluetoothGattCallback methods argument from BluetoothDevice to BluetoothGatt

Change name of BluetoothDevice#connectGattServer to BluetoothDevice#connectGatt
Add BluetoothGatt#getDevice to retrieve device from BluetoothGatt
Add BluetoothGatt#connect() to reconnect back to the server.
Make BluetoothGatt#close() public to clean up/unregister callback
Add BluetoothDevice.getType() to return int of
bug 8529188

Change-Id: Iebd9ac68cc7a64c43972e617dd3068f66c8ea0b2