am df336e2d: am c6ff6c40: Merge "gralloc: Clarify alloc stride for HAL_PIXEL_FORMAT_YCbCr_420_888" into jb-mr2-dev

* commit 'df336e2de4a57cc29815f4cdc75ee975676997d5':
  gralloc: Clarify alloc stride for HAL_PIXEL_FORMAT_YCbCr_420_888