Merge pull request #21048 from etiennesegonzac/bug-1027768

Bug 1027768 - Keep all role=system apps out of the cardview without breaking r=21
Merge pull request #21078 from vingtetun/bug1030664

Bug 1030664 - The contextmenu ui of the search app stays over results. r...
Conflicts:
	apps/search/js/search.js
Merge pull request #21009 from mnjul/bug_1029145_notifications_not_clear_when_app_lockscreen

Bug 1029145 - [B2G][Notification]Notifications do not clear from the status bar when the related app is behind the lockscreen. r=timdream
Merge pull request #20763 from guilherme-pg/bug1027429-honor-track-duration

Bug1027429 - Honor duration for track command in Find My Device
Merge pull request #21058 from vingtetun/bug1030675

Bug 1030675 - Handle search app crashes. r=kgrandon