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Change-Id: Ibf2377cd7491c7e0e9e9c9657e9e65eef1876ee3
Use TYPICAL_PROXIMITY_THRESHOLD instead of mProximitySensor.getMaximumRange()

Presto's proximity sensor returns values: 0.0f(near) or 5.0f(far).
mProximitySensor.getMaximumRange() must return proximity sensor's availible range, but it always return 0, so mProximityThreshold is also 0.

So boolean positive = distance >= 0.0f && distance < mProximityThreshold;  positive will never be
true.
The cause of this problem is proprietary sensor.msm8660.so, it must set proper Range and Resolution for proximity sensor.

Change-Id: Idf23ac50c8ec52bad5fafadbdf8af69dd66c273e