WiFi Calling: Change default value for the roaming setting to OFF.

Bug 19682545
Change-Id: Ia3fbcc3aba38cc6c5bae180b512a16f02f48f457
diff --git a/src/java/com/android/ims/ImsManager.java b/src/java/com/android/ims/ImsManager.java
index eaae299..e11c2e6 100644
--- a/src/java/com/android/ims/ImsManager.java
+++ b/src/java/com/android/ims/ImsManager.java
@@ -365,7 +365,7 @@
     public static boolean isWfcRoamingEnabledByUser(Context context) {
         int enabled = android.provider.Settings.Global.getInt(context.getContentResolver(),
                 android.provider.Settings.Global.WFC_IMS_ROAMING_ENABLED,
-                ImsConfig.FeatureValueConstants.ON);
+                ImsConfig.FeatureValueConstants.OFF);
         return (enabled == 1) ? true : false;
     }