Re-add default list item highlight

Typically we remove these hover and highlight effects for list items
that arenon-interactive where hover and keyboard navigation don't make
sense.

But that's not the case here; these list items are interactive (clicking
them toggles their checkbox) and therefore keyboard navigation does make
sense.

Accordingly, let's stop removing the default list item hover and
highlight effects to make this interactivity obvious and allow keyboard
navigation to be usable.

BUG: 465951
FIXED-IN: 5.27.3


(cherry picked from commit 00ed5916)