libstagefright: Fix to handle EAGAIN error on first read to source

 -Some of AV streaming clips are not played
 -In streaming use case when source does not have sufficent data it
  return error EAGAIN on first read request, player ignore this error
  and treat it as a first buffer.
 -Make the read request again to source on EAGAIN error.

Change-Id: I3feaccce757c17c4e80e6d62375c3d700ca29e72
AudioTrack: When paused, return cached playback position

An offload output can be re-used between two audio tracks having
the same configuration. A timestamp query for a paused track
while the other is running would return an incorrect time.
To fix this, cache the playback position on a pause() and return
this time when requested until the track is resumed.

CRs-Fixed: 612943

Change-Id: I54b5a851ee3fa2ceadc37e3f5c6af4f37b8f404a
android 4.4.3_r1.1 update

Change-Id: Ib92fafcf1647773d878cace81a3247f73f299134
Merge remote-tracking branch 'upstream/android-4.4' into android-4.4