Audio: Add Pause/Resume in AMR-WB tunnel recording

- Stopping AudioSource will be implemented when
  Pausing the SoundRecorder. However, it will
  be redone when stopping the SoundRecorder which
  will cause the exception.
- When it stays at Pause state, avoid to redo Stopping
  AudioSource

Change-Id: I2aeddd1ce4e3366660012b39241546ee305667fb