[autotest] Backport priority and timeout to R30.

BUG=None
TEST=None

Change-Id: Iaddac5fa559967758cb9c048cff3fdc8172d2285
Reviewed-on: https://chromium-review.googlesource.com/169193
Reviewed-by: Dan Shi <dshi@chromium.org>
Commit-Queue: Alex Miller <milleral@chromium.org>
Tested-by: Alex Miller <milleral@chromium.org>
65 files changed