Fix Signal strength display issue in Settings.

Bug: 20821065
Change-Id: Ib98e7b80f5ee331ef0adb8df706bb697f9fff008
diff --git a/src/com/android/settings/deviceinfo/SimStatus.java b/src/com/android/settings/deviceinfo/SimStatus.java
index 4fa5673..5a46578 100644
--- a/src/com/android/settings/deviceinfo/SimStatus.java
+++ b/src/com/android/settings/deviceinfo/SimStatus.java
@@ -278,11 +278,17 @@
                 display = mRes.getString(R.string.radioInfo_service_in);
                 break;
             case ServiceState.STATE_OUT_OF_SERVICE:
+                // Set signal strength to 0 when service state is STATE_OUT_OF_SERVICE
+                mSignalStrength.setSummary("0");
             case ServiceState.STATE_EMERGENCY_ONLY:
+                // Set summary string of service state to radioInfo_service_out when
+                // service state is both STATE_OUT_OF_SERVICE & STATE_EMERGENCY_ONLY
                 display = mRes.getString(R.string.radioInfo_service_out);
                 break;
             case ServiceState.STATE_POWER_OFF:
                 display = mRes.getString(R.string.radioInfo_service_off);
+                // Also set signal strength to 0
+                mSignalStrength.setSummary("0");
                 break;
         }
 
@@ -310,6 +316,7 @@
             if ((ServiceState.STATE_OUT_OF_SERVICE == state) ||
                     (ServiceState.STATE_POWER_OFF == state)) {
                 mSignalStrength.setSummary("0");
+                return;
             }
 
             int signalDbm = signalStrength.getDbm();