Add tryserver.chromium.linux:linux_chromium_gn_chromeos_rel to ANGLE CQ
to build test with use_ozone=1.

BUG=angleproject:1412

Change-Id: Ib4e851b95f7cfbb7099b531affccd14f08418725
Reviewed-on: https://chromium-review.googlesource.com/352318Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>