Handle clear all button show and hide functionality for low ram devices

Handle clear all button show and hide functionality for low ram devices

Hides the clear all button at the beginning and shows it when scrolling
the list up or when swiping an app away. The clear all button will not
hide when already shown. Users can also start the scroll gesture over
the clear all button to scroll the list.

Test: manual - use low ram device and go to recents and scroll
Change-Id: Ie2d22db9bdd66308ce8ef3acf77b9f707d638ade
Fixes: 65571889