AHB: add camera usage bits to vndk

GPU drivers need to handle AHBs from the camera HAL. Usually those AHBs
are allocated with AHARDWAREBUFFER_FORMAT_IMPLEMENTATION_DEFINED along
with gralloc camera usage bits. Adding the camera usage bits can help
the drivers to resolve the AHBs into implementation specific formats
with a stable ABI.

Test: build
Change-Id: I29d58bf9e61f012aaa30502e093bb1f33a9576ea