UiccController: add back registerForOn

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

Change-Id: I5fabd6dd75505aa3f6433437312392805485c4dc
Merge pull request #8 from CyanogenMod/cm-12.0

UiccController: add back registerForOn