Reset SensorEventListener when listener reenabled.

- Following disable and reenable of the WindowOrientationListener
the state was the same as before. State should be reset to default.

- Provide a Handler to the sensor task to deliver events on the
same Thread that WindowManagerPolicy operates on.

- Expand lock protection to all of WindowOrientationListener.

- Move WindowOrientationListener to policy package.

- Make SensorEventListenerImpl non-static.

Fixes bug 7964531.

Change-Id: I17cecf3d0b6d125cb3e4d7350c3adb3f62b684bd