Add edge-to-edge effect for grid picker

Screenshots:
- Mock: https://screenshot.googleplex.com/5GZPCniwyjZHUif.png
- Before: https://screenshot.googleplex.com/A4urU58jTrmdTx2.png
- After:
  - 3 buttons: https://screenshot.googleplex.com/7sBqvyN5xNf6p74.png
  - Gesture: https://screenshot.googleplex.com/7qYx3Mb25QmGePM.png

Bug: 185293474
Test: manual
Change-Id: Ifa9c1eb40c4553638d667150f2f38483f1f3d5f9