trigger mwext-Collection-testextensions-OCG (OCG branch)

Collection extension has two branch: master and OCG. Build change
against the OCG branch with the -OCG job, all other branches with the
-master job.

Had to expend the extension-unittests template to sneak in the -OCG job.

Change-Id: Id29ecd03394e8b3bf6b790aa5ce14112ad2c8b8a