audio_AudioBasicHDMI: Fail the test if HDMI is not selected

Fail the test earlier if HDMI is not selected on Cros device.

BUG=chromium:464661
TEST=Run the test on nyan_big using the default EDID where HDMI can not
be detected. Check test fails without playing audio.

Change-Id: Id20c12a8a553e8a5a808eddf41a96dfa037a8fcb
Reviewed-on: https://chromium-review.googlesource.com/261157
Reviewed-by: Kalin Stoyanov <kalin@chromium.org>
Reviewed-by: Wai-Hong Tam <waihong@chromium.org>
Commit-Queue: Cheng-Yi Chiang <cychiang@chromium.org>
Tested-by: Cheng-Yi Chiang <cychiang@chromium.org>
1 file changed