[Boca] Add features for new app ui changes

This adds features for recent ui changes, which will allow us to
control them and turn off the changes if needed.

Bug: 414621970
Change-Id: Id7b953efc351f056e312ce0768b4dd1c19fdbc55
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6543026
Reviewed-by: April Zhou <aprilzhou@google.com>
Commit-Queue: Benjamin Zielinski <bzielinski@google.com>
Cr-Commit-Position: refs/heads/main@{#1459627}