For single test execution we don't need to be running the watchdog
thread. This only serves to cause timeouts in slow running tests.

Adds a new method to keep the --batch-id argument in the list of
parameters so other functions can process them.

Bug: angleproject:5124
Bug: angleproject:5218
Change-Id: I958230149b7d79830802cd55f67f0190de607200
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2495282Reviewed-by: Tim Van Patten <timvp@google.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>