[iOS][Waffle] Fix rounded issue for the scrollview

With some configurations, because of rounded values, when scrolling
to the bottom, the bottom is not reached.
To make sure the More button disappears, when calling
-[UIScrollView setContentOffset:animated:], 1pt is added to make sure
the bottom is reached.

Fixed: 332719699
Change-Id: I1815877f31d6dd1f644c1508f2c1be65a69da7e0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5419128


Commit-Queue: Nicolas Dossou-Gbété <dgn@chromium.org>
Reviewed-by: Nicolas Dossou-Gbété <dgn@chromium.org>
Auto-Submit: Jérôme Lebel <jlebel@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1282049}