Add logging for notifications.

- Log notification launches
- Log notification swipes
- Fix logDragNDrop() to only log if the pre-drag ends (so it doesn't
  log a long-press that only shows shortcuts without dragging).
- Add shortcut rank to logs when launching deep shortcuts, where 0
  is the shortcut closest to the app icon (highest rank).

Bug: 34770729
Bug: 32410600
Change-Id: I99dcef9b6a71da2ef58e32397702bb137407b10f