BluetoothExt: Fix BluetoothFtpService shutdown

- If the adapter transitions to STATE_OFF before the intent
  is handled, the BluetoothFtpService won't shut down.
- Shut down the service if it's transitioning or already off

Bug: CYAN-4856

Change-Id: Id96fddaa443fe6b70eea880181b2d2fcc1d091de
Merge "BluetoothExt: Fix BluetoothFtpService shutdown" into cm-11.0