Add carrier config for WFC promo mode.

Adding new carrier config, defaulted to false, which allows a carrier to
promote the use of WFC when the device is connected to WIFI and WIFI
calling is disabled.

Bug: 27970317
Change-Id: I4904b7f006bae9f834816c1964025acf36b4ba84
diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index a5e50aa..900a157 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -285,6 +285,16 @@
     public static final String KEY_CARRIER_DEFAULT_WFC_IMS_ROAMING_ENABLED_BOOL =
             "carrier_default_wfc_ims_roaming_enabled_bool";
 
+    /**
+     * Flag indicating whether failed calls due to no service should prompt the user to enable
+     * WIFI calling.  When {@code true}, if the user attempts to establish a call when there is no
+     * service available, they are connected to WIFI, and WIFI calling is disabled, a different
+     * call failure message will be used to encourage the user to enable WIFI calling.
+     * @hide
+     */
+    public static final String KEY_CARRIER_PROMOTE_WFC_ON_CALL_FAIL_BOOL =
+            "carrier_promote_wfc_on_call_fail_bool";
+
     /** Flag specifying whether provisioning is required for VOLTE. */
     public static final String KEY_CARRIER_VOLTE_PROVISIONING_REQUIRED_BOOL
             = "carrier_volte_provisioning_required_bool";
@@ -841,6 +851,7 @@
         sDefaults.putBoolean(KEY_CARRIER_WFC_SUPPORTS_WIFI_ONLY_BOOL, false);
         sDefaults.putBoolean(KEY_CARRIER_DEFAULT_WFC_IMS_ENABLED_BOOL, false);
         sDefaults.putBoolean(KEY_CARRIER_DEFAULT_WFC_IMS_ROAMING_ENABLED_BOOL, false);
+        sDefaults.putBoolean(KEY_CARRIER_PROMOTE_WFC_ON_CALL_FAIL_BOOL, false);
         sDefaults.putInt(KEY_CARRIER_DEFAULT_WFC_IMS_MODE_INT, 2);
         sDefaults.putBoolean(KEY_CARRIER_FORCE_DISABLE_ETWS_CMAS_TEST_BOOL, false);
         sDefaults.putBoolean(KEY_CARRIER_VOLTE_PROVISIONING_REQUIRED_BOOL, false);