Bugzilla/1062819 pickup rebased/mobile connection core

I don't see the code has different behavior from the original one:
https://github.com/mozilla-b2g/gaia/blob/master/apps/system/js/airplane_mode.js#L17-L23

The old code does: when initSettings is called, get '*.enabled' once, and if it's true, unsuspend the settings.