Update spacing/layout of LS clock

- Only use the burn-in offsets on AOD. This means the clock will be in a
different position on LS compared to AOD.
- Align the top of the KeyguardSliceView (smart space) with the top of
the text of the clock (as opposed dto the top of the clock's view)
- Decrease bottom padding on KeyguardSliceTextView so that the DND icon
doesn't get cutoff when there's a large smart space info

Test: atest SystemUITests, manual
Bug: 170228350
Change-Id: I332300616e4218b6fcd24f837127a7eee487d4e7