Fix: wallpaper changes when changing lockscreen WP

Since LockscreenWallpaperPickerActivity did not override
cropImageAndSetWallpaper the homescreen wallpaper was changing
when selecting the default_wallpaper resource.

Change-Id: I26dd28e628a3ef701ad92a81aa80327d3ccba092
Fix side button visibility tracking.

Previously one could e.g. get legacy menu button being visible in
certain scenarios, like this one:
- Open legacy app, e.g. CatLog
- Invoke IME
- Lock screen
- Unlock screen
- Result: Menu button visible in keyguard

Change-Id: Ia796f73ec995ea1cc34d38f8aefdbccda7be7565
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