Merge pull request #14656 from etiennesegonzac/bug-937505-keypad-latency

Bug 937505 - Dialer Keypad - Touch Handling - Doing the expensive work after a tick to reduce the audio tone latency. r=rik
(cherry picked from commit 3bd9d999d30f9b5b0f2369b36d03b3d328f646fb)

Conflicts:
	apps/communications/dialer/js/keypad.js