mediaplayer: Switch to PAUSE state on suspend and STARTED on resume

- After repeated suspend/resume, the pause button will no longer work
  due to state mismatch in mediaplayer.
- Issue is caused due to a race condition between isPlaying() and
  AwesomePlayer resume.  If isPlaying() is called before Awesomeplayer
  is ready, mediaplayer goes into a dead end Pause state.  It is not
  possible to come out of this state unless we pause.  But we
  can't pause because mediaplayer thinks that it is already paused.
- This fix attempts to prevent the mismatch by changing the state to
  PAUSE on suspend and STARTED on resume.

Change-Id: I24ac964efc0cd70d79cafc870ceb2422473b5555
CRs-fixed: 260443, 260600