Introduce SystemSettingsCheckBoxPreference

  -Originally part of a3342e2 (Add back notification
   light settings.)

Change-Id: I474a14a1b395407f5ca273a5d6a3a7f03f7e4698
Settings: add double-tap to sleep in Advanced Settings

Adapted for cm-12.0

Change-Id: I910eb6624536b437d0bf14f64c1eeacafaa59cfa