Fix UnboundLocalError in _isUIAWindowHelper (#12859)
In #12854 the CanUseOlderInProcessApproach check was moved to run only when checking Office windows. However, it is also used to check whether to use UIA in Chromium.
Description of how this pull request fixes the issue:
Move this check before all usages, restoring the ability to use UIA in Chromium.
