plumb autotest args from CrosTestRequest into autotest driver

Update run_cros_test.py to have an additionaly autotest_args CLI flag to
align with recent changes to the CrosTestRequest proto. Update the
autotest_driver to plumb this new field into the autotest args when
calling test_that

BUG=b:256691471
TEST=PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python ./run_cros_test.py -host=localhost:2222 -board=zork -tests=tast.generic-list -results=$(pwd)/res -image zork-release.R109-15227.0.0_localchanges -autotest_args tast_list=example.Pass,example.Fail

Cq-Depend: chromium:3997478
Change-Id: I77b4755d29a6c5013084daba4a240bd046010129
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/4004058
Reviewed-by: Derek Beckett <dbeckett@chromium.org>
Commit-Queue: Jack Gelinas <jackgelinas@google.com>
Tested-by: Jack Gelinas <jackgelinas@google.com>
6 files changed