SystemUI: improve qs tile scroll handling

  - place detail view within bounds of expanded panel when it
   goes beyond the bottom of the screen

  - collapse qs panel when scrolling detail view (and letting go),
    disallowing it to get stuck at weird states that cut off the detail view

Change-Id: I775c0bb0022893a6a79fab93fb6cd92ba67b7213
Signed-off-by: Roman Birg <roman@cyngn.com>
(cherry picked from commit 1c7c0287)