SystemUI: Allow showing data type with roaming indicator on MSIM.

  If a device sets a system property "ro.config.always_show_roaming"
  the roaming indicator will not replace the data type icon, but create
  a new indicator alongside signaling that the sim is roaming.

Change-Id: I60ac97572b9b50e4809dbd809a8e5a2d0763542e
ProximitySensor: check for correct MaxRange value

Use TYPICAL_PROXIMITY_THRESHOLD for devices that returns incorrect mProximitySensor.getMaximumRange() value;

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: I0cf81fd20f210115cbd6db10c0070b12f1c57336