There is generally a small amount of time between the find call being
reported as finished and the find count results text being updated with
the correct number in the DOM, so the integration tests will fail if we
check the find results count text too soon.
This commit fixes the issue by using the `waitForTextToBe` helper
function to wait until the find count results text is what we expect it
to be. Note that we already use this helper function for this exact
purpose in other integration tests (related to reorganizing pages), and
it's also a little bit shorter/easier to read which cannot hurt.