Lockscreen: longpress on expand challenge handle

- Unsecure screen lock, long press will unlock the device
- Secure screen lock, long press and widget will fade into the background and secure method is displayed

Change-Id: I7d980f8e7e07226c97a64a63910a1410e6fb84c0

Conflicts:

	policy/src/com/android/internal/policy/impl/keyguard/KeyguardHostView.java