gralloc: Add support for lock_ycbcr

Fill the android_ycbcr struct for HAL_PIXEL_FORMAT_YCbCr_*_888
formats.

Change-Id: If0c7abf5e206bf982ad333da2dae57cbac302733
Gralloc: Fix HAL_PIXEL_FORMAT_YCrCb_420_SP structure init

The initialization was overrunning the end of the structure.

Bug: 8946915
Change-Id: I24b594316956f73366f8c1941c9270faf38e431d