Add snooze button to notification guts

- Expandable* - inject guts manager for snooze setup
- NotifContentView - snooze setup

Bug: 171817112

Test: manual
1) Disable snooze, send notif => snooze button hidden
2) Enable snooze, send notif => snooze button shows
       bottom right for expanded / heads up notif
       left of bubble button for conversations
       hidden for minimized notifs
3) Tap snooze button => snooze guts shows and works as before

Change-Id: I825ded613ec9c987bd0f0c7210a81e80b6c7296f