Fix updateIconBadges() in All Apps

Instead of notifyItemChanged(), we iterate over children of the
RecyclerView itself and call applyBadgeState() on affected icons.
This is the same logic we do for the workspace.

Issues this fixes:
- Icons flash when dismissing notifications
- Badge reappears on the icon while popup is open

Change-Id: I5c69d5c6bd47630c0241666b5f7f6f7ca97118f9