Add back video_watch
Summary:
We have fixed mrs_video_watch_over in D45367212, here we are adding it back to the diff-level test suite.
This Diff also updates the tests from enablement to both enablement+accuracy.
In the accuracy checking mode, the test will run the model in deterministic mode with batch size == 4. This should also be helpful to address the flaky tests like https://www.internalfb.com/intern/test/844425024890927?ref_report_id=0
Differential Revision: D46774325
fbshipit-source-id: 97c19a2c9b733fe5e6d456098a34e45c84a7d3b9
