audio: New audio format for FLAC

- Add string to enum conversion for new audio format
  FLAC

Change-Id: Ie49170947a6524aa7412855106d666b467104a93
audio: Handle sonification for last stream in stopOutput

-Low visibility stream is not muted during voice call when
played back to back.
-In startOutput, handleInCallSonification is called only for
first time i.e. mRefCount is 1. While in stopOutput, it is
called without any check on refCount.
This causes second notification stream to be played when
stopOutput of first stream unmutes the muted stream.
-Handle sonification while in call only for last stream in
stopOutput i.e. only if mRefCount is 1.

CRs-Fixed: 663101
Change-Id: If6cbf24aa814a115c98358883794a7c92aec0c86
audio_policy: Fix for audio routing speaker though BT is connected

- Speaker device is selected by getDeviceForStrategy() though BT is
  connected as mA2dpSuspended is still remaining as 'true' even
  after ending the voice call.
- This flasg is not updated by checkA2dpSuspend() as force usage
  for communication and record is still FORCE_BT_SCO after ending
  voice call.
- Modified condition check to set mA2dpSuspended to 'false' as soon
  as phone state is changed to MODE_NORMAL
  porting from change:Ib3a67268be33a10c6bcdf6437868990a92a06c2f

Change-Id: I86ebb66cd165e8009bfa6193d2ad9ab383996283
CRs-Fixed: 671810