sdk/platforms/android-25/data/res/values-mcc310-mnc580/config.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
/*
** Copyright 2013, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You my obtain a copy of the License at
**
**     http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
-->

<!-- These resources are around just to allow their values to be customized
     for different hardware and product builds. -->
<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">

    <!-- Configure mobile network MTU. Carrier specific value is set here.
    -->
    <integer name="config_mobile_mtu">1440</integer>

    <!-- Flag specifying whether VoLTE should be available for carrier: independent of
         carrier provisioning. If false: hard disabled. If true: then depends on carrier
         provisioning, availability etc -->
    <bool name="config_carrier_volte_available">true</bool>

    <!-- Flag specifying whether VoLTE TTY is supported -->
    <bool name="config_carrier_volte_tty_supported">false</bool>

    <!-- Flag specifying whether WFC over IMS should be available for carrier: independent of
         carrier provisioning. If false: hard disabled. If true: then depends on carrier
         provisioning, availability etc -->
    <bool name="config_carrier_wfc_ims_available">true</bool>
</resources>