Speed up test for closed caption state

This will speed up the tests in the case that the captions should be closed.
E.g. CMS Video Component : When start and end times are specified, a range on slider is shown, step: And Make sure captions are closed

Here is the report from the last test build of master: https://jenkins.testeng.edx.org/job/edx-all-tests-auto-master/lastCompletedBuild/SHARD=3,TEST_SUITE=cms-acceptance/testReport/(root)/CMS%20Video%20Component%20_%20When%20start%20and%20end%20times%20are%20specified,%20a%20range%20on%20slider%20is%20shown/