audio_policy: Fix for mute count mismatch for sonification strategy

- Sometime ring tone is not heard while in MT call

- During call mode, primary output ringtone/alarm stream mute count
  is incremented on startOutput and decremented on stopoutput
  for all Output requests.
    This is resulting side effect if stop output for non-primary outputs
  called, when no active streams available on primary output(mute count
  will not decrement)

- Add requested output check on start & stop output before calling
  handleIncallSonification API

Change-Id: Id4f328e2f9fc6820cecfbd73df11c871f8587aad
audio_policy : Fix for incorrect input device selection

BLUETOOTH_SCO_HEADSET is not avaibale in input devices list
for recording usecases. Add the same to allow VOIP applications
to select BLUETOOTH_SCO_HEADSET as input device when
BT is connected.

Change-Id: I5d5010ab396f85bf58573943c91fd815f39f57c1
CRs-fixed: 712950
stagefright: httplive: Fix deadlock for low duration clips

PlaylistFetcher buffers up to 3 * target-duration bytes of data,
but if a stream is slow (ie due to bad network conditions), a
buffer threshold of 10s is used to resume playback. This results
in an indefinite freeze as PlaylistFetcher has stopped buffering
before this threshold. Reduce the 10s threshold to be more in-sync
with PlaylistFetcher's buffering size.

CRs-Fixed: 745835
Change-Id: Ife846e7c5b4f9645895873d08250c4bee0164972