Contact Form 7 Shortcode in Template

try

<?php echo do_shortcode( '[contact-form-7 id="1234" title="Contact form 1"]' ); ?>

and what template do you use? single-portfolio.php

maybe to get it on both ( classic styled portfolios and advanced layout builded portfolios) it will be better to hook into footer.php for only portfolios.

try instead in your child-theme functions.php:

add_action('ava_before_footer', function() {
  if (is_singular( 'portfolio' )){
    echo '<div class="container">';
    echo do_shortcode( '[contact-form-7 id="1234" title="Contact form 1"]' );
    echo '</div>';
  }
});