Change the default --retry-limit for telemetry*unittests.
Change the default --retry-limit for telemetry*unittests.

Previously you had to pass the flag to get failures to be retried;
now we will retry failures by default if you run all of the tests
(i.e., do not specify any tests explicitly on the command line).

You can still pass --retry-limit=0 to turn off the retries and
--retry-limit=3 (or whatever) to force them on.

TBR=tonyg@chromium.org
BUG=402089

Review URL: https://codereview.chromium.org/468363002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#289554}
git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@289554 0039d316-1c4b-4281-b951-d872f2087c98

benschmaus/catapult,catapult-project/catapult,sahiljain/catapult,SummerLW/Perf-Insight-Report,catapult-project/catapult,catapult-project/catapult-csm,benschmaus/catapult,catapult-project/catapult,benschmaus/catapult,SummerLW/Perf-Insight-Report,SummerLW/Perf-Insight-Report,SummerLW/Perf-Insight-Report,sahiljain/catapult,benschmaus/catapult,catapult-project/catapult-csm,SummerLW/Perf-Insight-Report,catapult-project/catapult,catapult-project/catapult,sahiljain/catapult,sahiljain/catapult,catapult-project/catapult,catapult-project/catapult-csm,catapult-project/catapult-csm,benschmaus/catapult,sahiljain/catapult,catapult-project/catapult-csm,sahiljain/catapult,catapult-project/catapult-csm,catapult-project/catapult-csm,benschmaus/catapult,SummerLW/Perf-Insight-Report,benschmaus/catapult,catapult-project/catapult