Update popup to match redlines

- Update specs in dimens.xml and colors.xml
- Move notification count to top right, and keep "Notifications" in left
    - Also removed NotificationHeaderView and instead use FrameLayout
- Limit to 2 shortcuts instead of 3 if there are notifications
- Use SP instead of DP for text (b/35869307)

Bug: 35766387
Change-Id: I892640933ad6351946af3df6c805b98bb4e7cb50