Revert "SensorEventQueue: Allow setRate on sensor enable"

This reverts commit 320fd662. It's the wrong fix for the wrong problem. The main issue on 
devices like the JF is the presence of a new method (flush) in the 1.1
sensor API, which can't be invoked in older blobs and should
be addressed in the sensorservice itself.

Change-Id: I2f5fff41db7a11ed2e0f6650d1f1cecb5e2a03fb