Gestures: Ensure system stays awake for gesture handling

- Async broadcasts will allow the system to go back to sleep
before the receiver handles the event.  Acquire a wake lock
for a brief duration to allow the receiver time to receive
(and acquire it's own wake lock if needed) the intent.

Change-Id: I92ef57a95cf4cecfe9860ec070db958769034bea
Signed-off-by: MURA Stefano [STELIX PippoX3] <ssspinni@gmail.com>