Fix strstr constness

Change-Id: I796276c7efc9ac59596d05fc7b8ce93c2c83ac19
libeffects: Add zero check for enabledMsk and revEnabledMsk

If upper level doesn't send command EFFECT_CMD_ENABLE,
then it'll still call functions PreProcessingFx_Process
and PreProcessingFx_ProcessReverse. These functions will
continue to work and process because either enableMsk
or revEnableMsk is 0.

The result of condition:
"session->processedMsk & session->enabledMsk" is "0".
And "0" will be equal to "session->enabledMsk". Then
expression value will be true.

Change-Id: I6b1f636d67b759b9f96d0ae3440611dd5b782e5c
Signed-off-by: Yuan Zhang <yuanz@marvell.com>
stagefright: add ClockEstimator API and WindowedLinearFitEstimator

Change-Id: I74474c385848a8eab2ac0da7c069510378e2b217
AwesomePlayer: improve scheduling of video event to hit PTS

Change-Id: I7b19911acbde9b592b757b952d4ad63cd8efebed
Smooth out AwesomePlayer

Use clock estimator to smooth out audio time stamps.

Change-Id: Iec1ff30c011069d06ff8051fc4839d00895463d6
AwesomePlayer: use PTS for queueBuffer

Change-Id: I1c14ad4784c799c46cf06a14b0f00c5e4d01f718