Add compatibility code with mainline's configuration options for unlock

Change-Id: Ife2d6fad5cb1e7c846f5969401ee6dbc881aea3f
Merge branch 'qcril' into cm-10.2
Use2GOnlyCheckBoxPreference: fix NPE

Change-Id: Iacedd9f8eefb2d7f8ecdec4c0f1595448edbaf9f