The bots expect us to explicitly label "is_unexpected" for all
unexpected results (e.g. failures).

Also they construct a test filter from our test names so our result
names have to match the tests exactly. That means removing prefixes
like we have for the test suite name.

Bug: angleproject:3162
Change-Id: I1a02ff8e26545b10a8829a3ee47be91f7459aa65
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2345028Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>