Bug 1032629 - APN Settings UX refresh

https://bugzilla.mozilla.org/show_bug.cgi?id=1032629
Under the ```ril.data.default.apns``` setting you save the APN you set on boot. You should store all the APNs matching the MCC and MNC codes. You might be missing some APNs. Let's discuss tomorrow on IRC as it seems I wasn't myself clear enough ;).