gralloc: Add ITU-R standard info for YUV formats

These format qualifiers will help graphics decide which standard to use when
working with a YUV texture.

Bug: 8223174
Change-Id: I6ad464e6b070d3b375c5e07f03228308d15407cd
Signed-off-by: Iliyan Malchev <malchev@google.com>
gralloc: Set correct private gralloc format for video buffers

For IMPLEMENTATION_DEFINED pixel format, if the usage flag is
HW_VIDEO_ENCODER, the private gralloc format should be
HAL_PIXEL_FORMAT_NV12_ENCODEABLE.

Change-Id: I61e8aabe124179e8bebda5d50ad1d8681060b99a