vulkan: Add BGRA format support

This change adds handling to convert between the VULKAN and
AHARDWAREBUFFER enum values for the BGRA_8888 buffer format.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33485>
Bug: 491480133
Change-Id: I42b78349e02605238302ff9f101fc7252af0ab4c
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/mesa/+/1552296
Reviewed-by: Craig Stout <cstout@google.com>