[autotest] Allow lookups with failovers in global_config.
With this one can lookup a key in global_config, and if
it doesn't exist, get a value for a second specified key.
This allows `failovers`.
BUG=None
DEPLOY=
TEST=Ran suites.
Change-Id: Ia88200d77328033707aa292ff00924b677d0108f
Reviewed-on: https://chromium-review.googlesource.com/223376
Reviewed-by: Mungyung Ryu <mkryu@google.com>
Reviewed-by: Dan Shi <dshi@chromium.org>
Commit-Queue: Jakob Jülich <jakobjuelich@chromium.org>
Tested-by: Jakob Jülich <jakobjuelich@chromium.org>
2 files changed