Make arrow feel more connected to popup

- Clip the arrow that is overlapped by the popup, so that it doesn't
  show when that part of the popup is highlighted
- Animate the arrow first instead of last. Now the animation feels
  like one continuous motion as the arrow grows into the popup.

Bug: 111159923
Bug: 111006276
Change-Id: I22fb3037d950d55fe6c8ed4dc5345279874f0a3a