[DO NOT MERGE] Fix some mouse + list-item selection/scrolling issues

Any "touch" interaction now hides selection (since mouse
doesn't enable touch-mode, this wasn't happening anymore;
also, allowing listview to scroll an actual selection
off-screen would be very involved and risky).

The selector hilight remains (since mouse doesn't enter
touch-mode). This is a new scenario, so this change also
makes sure to hide the selector hilight when it's target
view is scrolled off-screen.

Bug: 67881712
Bug: 67720587
Test: Existing CTS tests still pass. Can now click list items
      via mouse even when scrolled. Visually checked that that
      selector hilight is not visible if off-screen.
Change-Id: Ia7b0fd7b247e8d9d9e609364a5500717df648fd9