libstagefright: Squashed commit of LPA/tunnel updates from CAF

libstagefright: Exceptions in using Tunnel mode decode

- Accumulate all known exceptions to a separate function

Change-Id: I61bbc288c9a087559db210e76141b8c57e67fff0
CRs-Fixed: 432080

libstagefright : Stability fixes for Tunnel Player (part 2)

- Synchronize b/w reset() and onPauseTimeout
- Synchronize b/w seekTo() and onPauseTimeout

Change-Id: Ia5cfc6b4dcc326ead440fba35d809d4f3f1b5a81
CRs-Fixed: 449122

Revert "Revert "libstagefright: Convert mono to stereo for LPA clips""

This reverts commit 0db8a19fb3216a8a83d5d6cbd5f1ccbf997a20d8.

libstagefright: Port Tunnel mode fixes to LPA

- Miscellaneous fixes for seek, pause/resume, EOS handling
- Miscellaneous fixes for synchronization between the decoder thread,
  TimedEventQueue and the player thread.
- This change is a port of a similar set of changes made for
  TunnelPlayer

Change-Id: I82c2904f7aedfb9c4f03200419fcba8b038e3d54

libstagefright: Avoid use of extra bytes to signal seek processed

- A few bytes were reserved in the buffer sent by Tunnel/LPA
  player to audio HAL to indicate a seek has been processed and
  there is no need to skip it.
- We won't need this method anymore as this can be fixed instead
  by synchronizing seekTo() and the extractor/decoder threads.

Change-Id: Ic02ae1699bb59e2f6b8d9fb599d0fa43fd3f19e3

libstagefright: LPAPlayer synchronization fixes

- synchronize b/w seekTo() and onPauseTimeout()
- synchronize b/w reset() and onPauseTimeout()

Change-Id: I29a4ccf02e28fe7b7c00e35a679ff2b5271ffb6f

libstagefright: TunnelPlayer performance tweaks

Some tweaks when TunnelPlayer is used for audio/video playback

- Keep the extractor thread at ANDROID_PRIORITY_NORMAL
- sched_yield() after reading a frame to give the video thread(s)
  (CallbackDispatcher and/or TimedEventQueue) to be scheduled

Change-Id: If0d86d629fd0e15aff917af8589472578cd28bf4
CRs-Fixed: 444041