Revert "Restore the notification background's hovered/pressed tints"

This reverts commit a47ea5ec42337124cfa1e72ee1d2ce12f486abdc.

Reason for revert: b/312841260

Fixes: 312841260
Change-Id: I28c06042d0e478bb76fb719c19deb9c8008050ea
Test: manual, post colorized notif before and after revert
Flag: NA
2 files changed