Had several validation errors with YUV ImageTests using Vulkan back-end.
This corrects those issues and tests now pass.

Initializing YUV AHardwareBuffers requires Android API 29. The CI bots
are not yet to Android 29 so this must be tested locally by compiling
with the appropriate api level in args.gn:
android32_ndk_api_level = 29
android64_ndk_api_level = 29

Test:
ImageTestES3.SourceYUVAHBTargetExternalRGBSampleInitData

Note: Some tests can run at api 26:
ImageTestES3.ClearYUVAHB
ImageTestES3.YUVValidation

Bug: angleproject:4852
Bug: b/172649538
Bug: b/175021871
Change-Id: I383d24faa9911f77a71bd9b764232ad519b54e9a
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2530454
Commit-Queue: Courtney Goeltzenleuchter <courtneygo@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Cody Northrop <cnorthrop@google.com>