title: Remove WooCommerce admin order action from order preview
body: <p>I want to remove, for shop-managers, the ability to mark an order as completed. To do so, I used the following based on <em>"<a href="https://stackoverflow.com/questions/48399729/hide-a-specific-action-button-conditionally-in-woocommerce-admin-orders-list/48401409#48401409">Hide a specific action button conditionally in Woocommerce admin Orders list</a>"</em> answer in my theme's functions.php file:</p>
  
  <pre><code>add_filter( 'woocommerce_admin_order_actions', 'custom_admin_order_actions', 900, 2 );
  function custom_admin_order_actions( $actions, $the_order ){
      if(isset(wp_get_current_user()-&gt;roles[0]) &amp;&amp; wp_get_current_user()-&gt;roles[0] == 'shop-manager') 
          unset($actions['complete']);
  
      return $actions;
  }
  </code></pre>
  
  <p>By this, I succesfully removed the complete button from the shop_order page. However, the shop-manager is still able to complete the order using the Complete button that appears in the order preview. To avoid this, I tried the next action after the previous one:</p>
  
  <pre><code>add_action( 'woocommerce_admin_order_preview_start', 'custom_display_order_data_in_admin' );
  function custom_display_order_data_in_admin(){
      // Call the stored value and display it
      echo '&lt;div&gt;Class = "button hidden wc-action-button wc-action-button-complete complete"&lt;/div&gt;&lt;br&gt;'; 
  }
  </code></pre>
  
  <p>However, this does not remove the button from the preview window because it does not substitute the line in the code.</p>
  
  <p>Is there a way to remove this ability from the shop_order page and the order preview at once? If not, how can I hide this button from the preview window?</p>