Merge pull request #18044 from etiennesegonzac/bug-992948-sysmsg-call-log

Bug 992948 - Use the telephony-call-ended sysmsg to record calls r=rik
(cherry picked from commit 04a7f8d951d1ed8bdbe5eaea75b3204792d24fa4)

Conflicts:
	apps/communications/dialer/js/calls_handler.js
	apps/communications/dialer/js/dialer.js
	apps/communications/dialer/js/handled_call.js
	apps/communications/dialer/test/unit/calls_handler_test.js
	apps/communications/dialer/test/unit/dialer_test.js
	apps/communications/dialer/test/unit/handled_call_test.js