au_test_harness: switch to the test image

The qemu image is the same as the test image, so we're not producing
it anymore, so switch to the test image directly.

BUG=b:187794257
TEST=CQ passes

Change-Id: I0c2e90efab625d05e2f13f9863898e534722e298
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crostestutils/+/2988463
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Jim Pollock <jmpollock@chromium.org>
Reviewed-by: Jaques Clapauch <jaquesc@google.com>
Commit-Queue: Jaques Clapauch <jaquesc@google.com>
Auto-Submit: Mike Frysinger <vapier@chromium.org>
1 file changed