sensorservice: Build legacy sensor fusion only if enabled.

Change-Id: I8c83a7af74b21f02ef172bbc84e82e0a5fff7547
sensorservice: Extend legacy sensor fusion with Orientation sensor.

Orientation sensor is only enabled when the device is not providing it.

Change-Id: Ib4d35fd94286dfe86e5d9ebad1f36cea6f220e5a