[f20] align testexeccontainer metadata/results with testexecserver

BUG=None
TEST=run_docker.py

Change-Id: Ia09a46adc9b592df614c110ea9512709d56df1fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/3114600
Tested-by: Derek Beckett <dbeckett@chromium.org>
Auto-Submit: Derek Beckett <dbeckett@chromium.org>
Reviewed-by: Jesse McGuire <jessemcguire@google.com>
Reviewed-by: Seewai Fu <seewaifu@google.com>
Commit-Queue: Derek Beckett <dbeckett@chromium.org>
2 files changed