Add --ozone-platform flag for VEA tests.

The main function of VEA test calls OzonePlatform::InitializeForUI.
It also needs --ozone-platform flag to correctly determine ozone
platform id.

BUG=chromium:467822
TEST=run the test on a freon device

Change-Id: If6466b53db1f5b37447cf1775ab1a35cb01e9877
Reviewed-on: https://chromium-review.googlesource.com/262096
Reviewed-by: Pawel Osciak <posciak@chromium.org>
Tested-by: Wu-cheng Li <wuchengli@chromium.org>
Reviewed-by: Wu-cheng Li <wuchengli@chromium.org>
Commit-Queue: Wu-cheng Li <wuchengli@chromium.org>
Trybot-Ready: Wu-cheng Li <wuchengli@chromium.org>
2 files changed