appchooserdialog: show all apps while searching
When you search, it's probably because what you want isn't visible among the small set of filtered apps. In this case, if we don't search through everything, it's annoying. So let's automatically show all apps when the user starts searching so it searches through all of them.
BUG: 464521 FIXED-IN: 5.27.1
(cherry picked from commit 28e3e3c0)