[iOS][CBD] Click on the settings done button instead of swipping down

The testChangeOptionsAndDismiss test is failling on iOS devices. Since
waitForAppToIdle did not work, my suspicion is that the swipe motion may
not be done correctly. This CL substitutes the swipe motion with a more
deterministic way of dismissing the view by tapping the 'done' button.
To note, that I cannot reproduce the issue locally.

Bug: 331757949, 333308808
Change-Id: I6b94d432d33d3bc06c51935f68fca7285c9d0fb2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5435575


Commit-Queue: Filipa Senra <fsenra@google.com>
Commit-Queue: Arthur Milchior <arthurmilchior@chromium.org>
Reviewed-by: Arthur Milchior <arthurmilchior@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1283904}