libstagefright: support 96kHz bitrate for FLACs

Previously, we would get this:

    E/FLACExtractor(  211): unsupported sample rate 96000

This commit lets us play these files now.

Change-Id: I01c14e95f6f21d33e12f30e8773b8c11c8b2ffe7
Noise will be heard if audio sample rate not matched with audio track

When audio sample rate which set to audio track is not the same with
the actual pcm data, noise will be heard. Fix the bug when write 8 bit
pcm samples.

AOSP commit: https://android-review.googlesource.com/#/c/59837/

Change-Id: Idcb0d7b0e9aaa250dd22b758c8337e23d1706049
Signed-off-by: Ming Zhou <b42586@freescale.com>
Signed-off-by: guoyin.chen <guoyin.chen@freescale.com>
libstagefright: support for disabling buffer metadata

- Metada mode video recording is enabled by default.
- use setprop debug.camcorder.disablemeta 1 to disable metadata mode recording.

Change-Id: I422c49c0ace0c3a3e1f4459c7e4bf29e70af763a