stagefright: provide a custom key to prefer adaptive playback

Provide a custom key "prefer-adaptive-playback" that can be
set in MediaFormat by java apps or by Native players to
prefer adaptive-playback over dynamic buffering

Change-Id: Ic02fc9f1d68fd9803ec154498a86e2537efcce85
av: Additional ifdefs for QCOM DirectTrack

 * Tunnel and LPA mode on legacy QC devices requires the DirectTrack
   code path, which going forward has been deprecated.
 * In order to properly support QC features on 8974, this needs broken
   out in order to not cause problems on new devices.
 * With this patch, QCOM_HARDWARE will enable features common to all
   QC platforms (including legacy), and legacy support will
   automatically be enabled based on the use of driver variant and
   value of BOARD_USES_LEGACY_ALSA_AUDIO.

Change-Id: I1da503309963734fd6603472fb87dd9c95c7b7b5
Revert "Camera: Rotate display if app doesn't use setDisplayOrientation."

This reverts commit 4b52ba4cec578962ec2695b7d10abdd32f088065.
Merge remote-tracking branch 'github/cm-11.0' into test