odoo-survey-addons/survey_attachment/views/survey_user_input_line.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

  <record id="survey_user_input_line_form" model="ir.ui.view">
    <field name="name">survey_attachment survey.user_input_line form</field>
    <field name="model">survey.user_input_line</field>
    <field name="inherit_id" ref="survey.survey_user_input_line_form"/>
    <field name="priority">20</field>
    <field name="arch" type="xml">
      <xpath expr="//field[@name='answer_type']" position="after">
        <field name="file" filename="filename" attrs="{'invisible': [('answer_type','!=','upload_file')]}"/>
        <field name="filename" invisible="1"/>
      </xpath>
    </field>
  </record>

</odoo>