[iOS] Update description in the plus address sheet

Screenshot: https://screenshot.googleplex.com/992yAHpatNCriGb.png
Bug: 343153116
Change-Id: I1635f4b0df0676995cd9e6af94966e24b3d86a4e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5607747


Reviewed-by: Jan Keitel <jkeitel@google.com>
Commit-Queue: Vidhan Jain <vidhanj@google.com>
Cr-Commit-Position: refs/heads/main@{#1312682}