OpenEUICC/app-common/src/main/res/xml/network_security_config.xml

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config>
        <trust-anchors>
            <certificates src="@raw/symantec_gsma_rspv2_root_ci1"/>
            <certificates src="system"/>
        </trust-anchors>
    </base-config>
</network-security-config>