Update carrier text when phone service state is changed

The carrier text is not updated when the phone service state has
changed. To solve this issue, the EmergencyCryptkeeperText view should
receive the KeyguardUpdateMonitorCallback#onRefreshCarrierInfo().

Bug: 37331677
Test: visual

Change-Id: I359991688552b731eaa02f443902eb7bdc894d10
(cherry picked from commit 76c36c4dc5)

packages/SystemUI/src/com/android/systemui/statusbar/policy/EmergencyCryptkeeperText.java

@@ -47,6 +47,11 @@ public class EmergencyCryptkeeperText extends TextView {
         public void onPhoneStateChanged(int phoneState) {
             update();
         }
+
+        @Override
+        public void onRefreshCarrierInfo() {
+            update();
+        }
     };
     private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
         @Override