Enable VoLTE with overlay configuration allowing disabling.

Bug: 17134661
Change-Id: Ie6262b2b39848a13729a4b9d6acad10ebb91636b
diff --git a/core/res/res/values-mcc311-mnc480/config.xml b/core/res/res/values-mcc311-mnc480/config.xml
index e3d8420..1c83644 100644
--- a/core/res/res/values-mcc311-mnc480/config.xml
+++ b/core/res/res/values-mcc311-mnc480/config.xml
@@ -38,4 +38,9 @@
         be disabled) but individual Features can be disabled using ImsConfig.setFeatureValue() -->
     <bool name="imsServiceAllowTurnOff">false</bool>
 
+    <!-- Flag specifying whether VoLTE & VT should be allowed on device: independent of the
+         carrier provisioning. If false: hard disabled. If true: then depends on carrier
+         provisioning, availability etc -->
+    <bool name="config_mobile_allow_volte_vt">false</bool>
+
 </resources>
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index f702b95..a59a489 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -1641,6 +1641,11 @@
         be disabled) but individual Features can be disabled using ImsConfig.setFeatureValue() -->
     <bool name="imsServiceAllowTurnOff">true</bool>
 
+    <!-- Flag specifying whether VoLTE & VT should be allowed on device: independent of the
+         carrier provisioning. If false: hard disabled. If true: then depends on carrier
+         provisioning, availability etc -->
+    <bool name="config_mobile_allow_volte_vt">true</bool>
+
     <bool name="config_networkSamplingWakesDevice">true</bool>
 
     <string-array translatable="false" name="config_cdma_home_system" />
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index 1cb7b17..71b782d 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -1956,6 +1956,7 @@
   <java-symbol type="attr" name="preferenceFragmentStyle" />
   <java-symbol type="bool" name="skipHoldBeforeMerge" />
   <java-symbol type="bool" name="imsServiceAllowTurnOff" />
+  <java-symbol type="bool" name="config_mobile_allow_volte_vt" />
   <java-symbol type="bool" name="useImsAlwaysForEmergencyCall" />
   <java-symbol type="attr" name="touchscreenBlocksFocus" />
   <java-symbol type="layout" name="resolver_list_with_default" />