audio_policy: Add EVRCB & EVRCWB formats

  * needed for msm7x27a and msm8660
  * needed to compile audio hal from caf

Change-Id: Ibac3cf0b58de0bb6ee621e0498322318464492a0
libhardware_legacy: Add support for DirectTrack

-Add new APIs to AudioStreamOut class.
-Add audio output flags to openOutputStream.

(cherry picked from commit c2238e581c815dbf33625011ad32a97067d1ab52)
(cherry picked from commit 87d4ab5eee4124403012cb3e5440d36eb0df9586)

Conflicts:
	include/hardware_legacy/AudioHardwareInterface.h

Change-Id: I8a1f51542658655b254f629b648ac6b1bb0113f3