Add edge-to-edge effect for CategorySelectorFragment

Screenshots for wallpaper:
- 3 buttons: https://screenshot.googleplex.com/9dckBMzNEzheA7K.png
- 3 buttons (bottom): https://screenshot.googleplex.com/4Ez28WkavJLBjyp.png
- Gesture: https://screenshot.googleplex.com/9dckBMzNEzheA7K.png
- Gesture (bottom): https://screenshot.googleplex.com/AjGGqfDL8Y8eXPT.png

Bug: 185293474
Test: manual
Change-Id: I2a3f5680840349c7862fd4e0bea0e2aa39ce2e43
1 file changed