Keeping the screen on during gesture detection.

1. During gesture detection we are not injecting the events we receive
   since we do not want the accessibility focus to move as a result of
   the hover event of the gesture. Because of that it was possible that
   we consume all events since the user performs only gesture to navigate
   resulting in the screen being off while the user is actively interacting
   with the device. Now we are poking the user activity in the power
   manager to keep the screen on.

bug:6485171

Change-Id: I06a09c5297f01bef5e20d471cee76fa7aae0c4fe