Bug 1069286 - No tactile feedback when dialling a number

And if it's possible, I think to put vibration duration in mozSettings as 'keyboard.vibration.duration' or something like that is better than put it here. I know in the FeedbackManager of Keyboard app it is hardcoded, and the root cause that you need to modify LockScreen is the original LockScreen implement its own keypad rather than using the existing keyboard app, but I think this is still a cross-app setting value, which I believe it's better to be a mozSettings value. Otherwise, we need to maintain two copy of this value unreasonably.