CrOS GMC V2: Use page pagination to display multiple media items

When there are multiple media items in the quick settings view, show
pagination dots in the bottom of the media view and users are able to
switch between media items by clicking on the dots.

Fix more bugs in PaginationView that were found when using it for our
purpose.

Screenshot: https://screenshot.googleplex.com/9zKv6P4Yh5BDq3m

Bug: 1406703
Change-Id: I5ea0736e14f3a706992c5c75fc555c466af9a526
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4375909


Reviewed-by: Elaine Chien <elainechien@chromium.org>
Commit-Queue: Yiren Wang <yrw@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1123737}