[Autotest] Add a global in control.srv generated by rpc interface for suite job

This CL is splitted from CL 58110 to get prod ready to run hwtest for it. In CL
58110, the code passes the selected devserver url from create_suite_job to
dynamic_suite as an argument in dynamic_suite.reimage_and_run method.

BUG=chromium:236540
TEST=tested with run_suite in local workstation
DEPLOY=apache

Change-Id: I3b95686af04e40444a5f482e7fd22a49d771b3f5
Reviewed-on: https://gerrit.chromium.org/gerrit/59091
Tested-by: Dan Shi <dshi@chromium.org>
Reviewed-by: Alex Miller <milleral@chromium.org>
Commit-Queue: Dan Shi <dshi@chromium.org>
1 file changed