vibrator: Add a threshold to filter out some short vibration cases

Some app will use short vibration to implement haptics effect and
those cases will feel a delay from the motion awareness mechanism.

We add this patch to filter out those cases since those behaviors
beyond the motion awareness mechanism scope.

Bug: 162346934
Test: UT test
Signed-off-by: chasewu <chasewu@google.com>
Change-Id: Iee8d5993f040126243d90330f03b897970c70c1b