[TASK] Fix flaky Acceptance Tests

The current default timeout to wait for elements is 10 seconds.
Turn up to 30 sec to stabilize the situation.

Change-Id: I2dd6cbe14a7d05cfe3cf6f7ad3437e0b235c96f1
Resolves: #83836
Releases: master, 8.7
Reviewed-on: https://review.typo3.org/55634


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Tested-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>