Add pagination dots and fix animation of user switcher.

- Adds pagination dots to user switcher dropdown.
- Adds device name text view for when devices are associated with users.
- Fixes the layout of the user grid to handle changing height for
  proper animation.

Bug: 65423882
Tested on Mojave with longer animation times to ensure correctness.

Change-Id: I54ae5cc93f9caa9d6c4a5c2c7e9e2488a6257001
(cherry picked from commit 0de35b5386ad7e00f13a7611fce36ca990b201e0)