contract/subscription_oca/views/product_template_views.xml

<?xml version="1.0" ?>
<odoo>
    <record id="product_template_form_view" model="ir.ui.view">
        <field name="name">product.template.sub.form</field>
        <field name="model">product.template</field>
        <field name="priority" eval="8" />
        <field name="inherit_id" ref="product.product_template_form_view" />
        <field name="arch" type="xml">
            <xpath expr="//page[@name='sales']" position="inside">
                <group>
                    <field name="subscribable" />
                    <field
                        name="subscription_template_id"
                        invisible="not subscribable"
                    />
                </group>
            </xpath>
        </field>
    </record>
</odoo>