Summary:
Feed the first-party oncall data through to the testpilot
invocation.  This will set the owner of the test in continuous runs.

The oncall is passed through via the sandcastle module, which means
that you will have to manually pass it through for local testing
(see test plan), but it should automatically get picked up when
sandcastle schedules the `test` step of the job.

Reviewed By: chadaustin

Differential Revision: D17146802

fbshipit-source-id: a4f0e65853a46ed8709594c96db859ede2530b00