Add Wi-Fi calling state setting to telephony interfaces

Change-Id: I01029ade0eb1ff981cb92a536d042a02129a053f
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 9332578..d7f6a0b 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -2483,6 +2483,14 @@
             NOTIFICATION_SOUND
         };
 
+        /**
+         * When to use Wi-Fi calling
+         *
+         * @see android.telephony.TelephonyManager.WifiCallingChoices
+         * @hide
+         */
+        public static final String WHEN_TO_MAKE_WIFI_CALLS = "when_to_make_wifi_calls";
+
         // Settings moved to Settings.Secure
 
         /**