Migrate to androidx namespace for support library.

Fixes: 77483560
Test: build KitchenSink, deploy and test through fragments
Test: build and launch UxRestrictionsSample
Change-Id: I539c71464f5a486c9a9373bbbcae8ac14d24e477
Merged-In: I539c71464f5a486c9a9373bbbcae8ac14d24e477
(cherry picked from commit d12cd7712b0498fac816bc1fa10299a1127f711b)
25 files changed