This instead only sets the timeout when tests start to run. That
way the timeout should always be at least the default timeout
and we won't get into a situation where the watchdog times out
the test immediately when the test starts.

Bug: angleproject:5562
Change-Id: I6b12bb8fe8edcf35f46ba4fb106fdf80ff9402a1
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2637182Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>