ST_ERICSSON: support for latency

manualy ported from
commit e8cfc22c08e32b463186362ed40abb4d34eedca8
Author: Naveen Agarwal <naveen.agarwal@stericsson.com>
Date:   Thu Apr 5 21:06:59 2012 +0000

    Add support for update of audio output latency on Snowball

    Adds mechanisms enabling AudioPlayer to receive updated latency values
    for the audio output. The possibility to update the latency value is
    needed because the latency values for some devices (e.g., A2DP devices)
    are not known until they have been opened. Latency value updates will
    also occur when output device is exchanged on-the-fly during playback
    (e.g., audio output is moved from headset to A2DP device).

    This patch modifies the MediaPlayerService::open() function declaration
    which is part of an Android internal interface. Although, this is a
    backward compatible change since only a default parameter is added.

    ST-Ericsson ID: 372587

    ST-Ericsson FOSS-OUT ID: STETL-FOSS-OUT-12221

    Introduce backward compatible changes to exposed interfaces

Change-Id: I0ac7eb7647d00c92719078aa5260d37fea795f15

Conflicts:
	include/media/AudioParameter.h
	include/media/AudioSystem.h
	include/media/AudioTrack.h
	include/media/MediaPlayerInterface.h
	include/media/stagefright/AudioPlayer.h
	media/libmedia/AudioParameter.cpp
	media/libmedia/AudioSystem.cpp
	media/libmedia/AudioTrack.cpp
	media/libmediaplayerservice/MediaPlayerService.cpp
	media/libmediaplayerservice/MediaPlayerService.h
	media/libstagefright/AudioPlayer.cpp
	services/audioflinger/AudioFlinger.cpp