Merge pull request #21776 from azasypkin/bug-1022575-on-delete-v2.0

 Bug 1022575 - Received SMS store (without text) on check balance. Listening "ondelete" event for the deleted threads. r=julien
Merge pull request #21834 from KevinGrandon/bug_1029902_low_memory_features

Bug 1029902 - [Vertical Homescreen] Implement device capability configuration
Merge pull request #21825 from empoalp/bug_1038616

Bug 1038616 - [Dialer] Busy tone not playing