virtgpu: don't use emulated HW use flags with gbm host

If the virtgpu backend is running with host gbm enabled, don't add
camera/encoder/decoder use flags to formats that aren't supported by
host gbm.

BUG=b:174522583
TEST=android.media.cts.MediaRecorderTest#testProfileAvcBaselineLevel1

Change-Id: I69584b63d07974c46f8154637947c7f891fdfae0
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/minigbm/+/2586132
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Tested-by: David Stevens <stevensd@chromium.org>
Commit-Queue: David Stevens <stevensd@chromium.org>
1 file changed