contract/agreement_sale_condition_base/data/agreement.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <record model="agreement" id="agreement_standard">
        <field name="name">Standard Template</field>
        <field name="code">standard_tmpl</field>
        <field name="agreement_type_id" ref="agreement_type_standard"/>
        <field name="is_template" eval="True"/>
  </record>

  <!-- data loaded from xml does not call write, so the override is not called -> force it-->
  <function model="agreement"
            name="write"
            eval="(ref('agreement_standard'), {'agreement_type_id': ref('agreement_type_standard')})"/>
</odoo>