Enforce READ_PRIVILEGED_PHONE_STATE on getEmergencyCallbackMode

BUG: 67750821
Test: None
Change-Id: I81c997f3a186df3d2336ffff1eea2aa2a15cad42
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index d199100..1803560 100644
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -39,7 +39,6 @@
 import android.os.Message;
 import android.os.Messenger;
 import android.os.PersistableBundle;
-import android.os.Process;
 import android.os.ResultReceiver;
 import android.os.ServiceManager;
 import android.os.UserHandle;
@@ -3850,7 +3849,9 @@
      * @return true if phone is in emergency callback mode
      * @param subId sub id
      */
+    @Override
     public boolean getEmergencyCallbackMode(int subId) {
+        enforceReadPrivilegedPermission();
         final Phone phone = getPhone(subId);
         if (phone != null) {
             return phone.isInEcm();