UiccController: add back registerForOn

It was removed in a77b4218dc29c2cda3eea69e6642821598849898, but this is
required for many devices.

Change-Id: I5fabd6dd75505aa3f6433437312392805485c4dc
Merge branch 'cm-12.0' of https://github.com/CyanogenMod/android_frameworks_opt_telephony into cm