libstagefright: Allow using camera recording buffer as input for encoder

Vastly improves camcorder framerate when recording 720p videos (from ~18fps to ~29,5fps)
Useful for SEMC 2011 devices, which don't have a powerful enough cpu
Can be enabled with global cflag SEMC_ICS_CAMERA_BLOB

Change-Id: I6dce1390bd611e9ce318d2aef0da22f843a2632b
libstagefright: Fix video encoder input buffer

Ported from cm10

Needed to avoid the encoder eating up all input buffers,
which leaves no buffer left for the camera sometimes

Change-Id: I0432cd87a9defd08725ac8831d7376edb98d7e18
Merge remote-tracking branch 'omni/android-4.4' into android-4.4