sensors: Force a minimum interval between gyro state changes

The gyroscope will mess up the entire sensor pile if it gets deactivated
less than around 150 msec after it's enabled, which does happen
with some overly aggressive apps. Prevent this simply by delaying all
gyro disablements by 200 msec.

Change-Id: I8212a8aa4beb22a241ed63cc8d1471b4fea3d0b6