storage_file/data/ir_cron.xml
<?xml version="1.0" encoding="utf-8"?>
<odoo noupdate="1">
<record forcecreate="True" id="ir_cron_clean_storage_file" model="ir.cron">
<field name="name">Clean Storage File</field>
<field eval="True" name="active"/>
<field name="user_id" ref="base.user_root"/>
<field name="interval_number">1</field>
<field name="interval_type">days</field>
<field name="numbercall">-1</field>
<field eval="False" name="doall"/>
<field eval="'storage.file'" name="model"/>
<field eval="'_clean_storage_file'" name="function"/>
<field eval="'()'" name="args"/>
</record>
</odoo>