[BCIV] Fix white toolbar bug

We assumed all tab switches/interactability changes resulted in the
toolbar being locked for 3 seconds, but this was not true.

Fix this by not listening to onInteractabilityChanged, but on hide/show
instead, and updating the OffsetTag based on the current visibility
constraints instead of assuming the controls start out as being locked.

Bug: 360183449
Change-Id: Ib2616b804efc7585a78d31e6af3f4abec863064a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5807536
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Commit-Queue: Peilin Wang <peilinwang@google.com>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1345632}