GL: Implement EXT_YUV_target Add test coverage of YUV format sampling as RGB or directly as YUV and rendering as YUV using layout(yuv). Initializing YUV AHardwareBuffers requires Android API 29 so ANGLE must be compiled with: android32_ndk_api_level = 29 android64_ndk_api_level = 29 The following tests can still run with Android API 26 because they don't need to initialize the buffer: ImageTestES3.ClearYUVAHB ImageTestES3.YUVValidation Bug: angleproject:4852 Bug: b/172649538 Change-Id: I4fe9afb2a68fb827dc5a5732b213b5eb60d585ac Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2517562 Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>