libhardware_legacy: Add support for DirectTrack

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

Change-Id: Idcbca5d8ea3bd3f7ea008e42ae685f3f1b24dc6c
(cherry picked from commit c2238e581c815dbf33625011ad32a97067d1ab52)
(cherry picked from commit 87d4ab5eee4124403012cb3e5440d36eb0df9586)

Conflicts:
	include/hardware_legacy/AudioHardwareInterface.h
libhardware_legacy: Add MSM specific flags, devices and channels.

- Add support for MSM flags, devices and channels

Change-Id: I88ff548a4ac0629ea80a0103648b5d8f7acfd7da
(cherry picked from commit 47fc1126a6d6d4e7716b6ca65490550744c909f2)
(cherry picked from commit dc8add29ede96579400e07721ee2510cf40da629)

Conflicts:
	audio/AudioPolicyManagerBase.cpp
	include/hardware_legacy/AudioSystemLegacy.h