Merge "Deal with unknown signal strength level comes from Telephony" am: 2327cfc5

             */

            private int gsmAsuToSignal(SignalStrength signalStrength) {

                int asu = signalStrength.getGsmSignalStrength();

                if      (asu >= 16) return 5;

                if      (asu == 99) return 0;

                else if (asu >= 16) return 5;

                else if (asu >= 8)  return 4;

                else if (asu >= 4)  return 3;

                else if (asu >= 2)  return 2;