libstagefright: Handle offload fallback for WAV content

- For WAV content there is no OMX Source, use the AudioTrack
  as OMX Source for fallback.

Change-Id: Ifeaeb2cf8dd777d167b74eebd11803b7f130e857
stagefright: Fix AV sync issue for cached audio sources

Non-HTTP sources may continue to fetch audio data after video has
already seen a seek request causing audio to run ahead. When video
sees a seek request, audio should pause, resuming once it too has
handled the seek request.

Change-Id: Iddbf3d79f29bbe8bcdb4b07338c4a00734acd8e2
libstagefright: Fix in AudioPlayer media time mapping

- Use seektime as the play position when player is still
  seeking.

Change-Id: Id92a07e3291280b17b83d53ff2e218acc3ee6020
audioflinger: Fix cleanup of asynccallback thread

AsyncCallbackThread will not be spawned if the output
profile does not support non-blocking output or if the HAL does not
support set_callback API.

Add a check for validity of callback thread object before deleting it.

Change-Id: I3943f80abba3fd7f18fbfd6190bb884f773772b5
ACodec: Add video codec fallback logic

- Check while onAllocate if codec is capable of handling video
  resolution. If not fallback\retry other capable components in the
  list

Change-Id: I3203275be23651dbd9ad7a7397526ac601a3350a