Merge changes from topics "barring-cp", "nri-rplmn"

* changes:
  Allow Nullable Registered PLMN
  Return the RPLMN from NetworkRegistrationInfo
  Expose PreciseDataConnectionstate#getApnSetting()
  Skip sanitizing location info for Null Barring CID
  Remove BarringInfo#isServiceBarred()
  Introduce a new RIL request constant to support getBarringInfo.
  Update BarringInfo as Barring HAL date stuctures updated
  Add a BARRING_TYPE_UNKNOWN for Unreported Barring
  Add Callback to notify changes of barring status