Add support for showing border for desktop tile

When a external keyboard is connected and ENABLE_KEYBOARD_QUICK_SWITCH
feature flag is enabled, we highlight the selected tile in overview.
Add support to the new desktop tile to show the highlight.

Bug: 269342116
Test: connect an external keyboard, use alt+tab to open overview and
  switch between the tiles
Change-Id: I29ac5864776a9a251ecdb0cb4b741b12747de564