storage_backend/storage_image/security/res_group.xml

<?xml version="1.0" encoding="UTF-8" ?>
<odoo>
    <record model="res.groups" id="group_image_manager">
        <field name="name">Image Manager</field>
        <field
            name="users"
            eval="[(4, ref('base.user_root')), (4, ref('base.user_admin'))]"
        />
    </record>
</odoo>