'Beta' tag for themed icon toggle

Spec:
  https://www.figma.com/file/f5kMYkfuvjkLr9VvXTsy2e/Silk-Sounds?node-id=2848%3A411

Screenshot:
  https://screenshot.googleplex.com/8KAuyMEqBCKeE2M.png
  https://screenshot.googleplex.com/9uB2puzws8tepyr.png

Bug: 192629966
Test: manual
Change-Id: I654f105d5599ddd5fde88de4516364116cbd45f9
5 files changed