Fix 5444675: Fix vibrate regression on Pattern and PIN unlock screens.

This fixes a regression caused by a resource change to the vibrate
pattern.  It used to contain an array of delays and values.  Now it has
another mode with just one value with an associated change to the vibrate
API.

Instead of using a custom vibration pattern, it now just follows the system
vibrate pattern for HapticFeedbackConstants.VIRTUAL_KEY, which is shared by the
home key, among other things.

Change-Id: Ib58493a96a42383955ae59f8ac3865bb46a86a31