Increased timeout for element count in HTML test

Addresses this failure in master: https://jenkins.testeng.edx.org/job/edx-all-tests-auto-master/411/SHARD=3,TEST_SUITE=cms-acceptance/

The screenshot shows that the HTML component *was* created successfully, but the test timed out waiting for it.  This is a very rare failure, so I think this is a reasonable precaution.

I also refactored the code slightly for brevity.

@jzoldak