I think this is a reasonable test to have, but it's not a test of setting the property in Studio. You plan to have that test in your next pull request, so great.

I do think though that it is worth modifying the text for this test so it is obvious what you are testing.

You are toggling the show captions option on the video (test both turning it off and then toggling it back on). And then you want to verify that the captions either do or do not show (not "by default", but in actuality).