Add haptic vibration feedback on in-call buttons.

For buttons which appear an first-class actions in the in-call screen,
add haptic feedback.  This feedback ignores the system settings, meaning
that it vibrates when buttons are touched regardless of the system
settings for vibrating on keypress.

Bug: 18388068
Change-Id: Ifadc973af9bcdfdfdc9d51b1c927b08d93714a58