app-grid: Collapse favorites on init
If there's no favorites, the favorites_changed callback is never fired, which means there's an empty revealer (and separator) that will suddenly collapse when a search is performed.
This is also included in !1418 (closed) as it's required to get consistent screenshot results. But I figured it's also just a minor fix that would be useful to get out the door independently from that other (monster) MR :)
Edited by Sam Day