android_device_google_gs-common/pixel_ril/compatibility_matrix.xml

<compatibility-matrix version="1.0" type="framework" level="7">
    <hal format="aidl" optional="true">
        <name>vendor.google.ril_ext</name>
        <version>1</version>
        <interface>
            <name>IRilExt</name>
            <instance>slot1</instance>
            <instance>slot2</instance>
        </interface>
    </hal>
</compatibility-matrix>