[ios] Give flexibility for two lines in Most Visited Tiles

Updating the tile's titleLabel.preferredMaxLayoutWidth to match the
label's width constraint will allow autolayout to recognize that
a second line is needed sooner. Defining the module container's height
in a constraint will also ensure that enough space is allocated to
each module.

Fixed: 1338131
Change-Id: I25c5f45d03ddc944197c6a9427ff0f1f2ac33683
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3736096
Reviewed-by: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1019696}