assets/carrier_config_001001.xml

<?xml version='1.0' encoding='utf-8' standalone='yes' ?>
<carrier_config_list>
    <carrier_config>
        <boolean name="carrier_volte_available_bool" value="true" />
    </carrier_config>
    <carrier_config spn="null">
        <boolean name="carrier_volte_available_bool" value="true" />
    </carrier_config>
    <carrier_config spn="^Tes.*">
        <boolean name="carrier_volte_available_bool" value="true" />
    </carrier_config>
    <carrier_config imsi="^001001.*">
        <boolean name="carrier_volte_available_bool" value="true" />
    </carrier_config>
</carrier_config_list>