title: Gravity Forms add attachment to user notification
body: <p>I am using the following code from Gravity forms to attach a file to the user's notification:</p>
  
  <pre><code>add_filter( 'gform_notification_55', 'add_attachment_pdf', 10, 3 ); //target form id 2, change to your form id
  function add_attachment_pdf( $notification, $form, $entry ) {
      //There is no concept of user notifications anymore, so we will need to target notifications based on other criteria,
      //such as name or subject
      if( $notification['name'] == 'User Notification' ) {
          //get upload root for WordPress
          $upload = wp_upload_dir();
          $upload_path = $upload['basedir'];
  
          //add file, use full path , example -- $attachment = "C:\\xampp\\htdocs\\wpdev\\wp-content\\uploads\\test.txt"
          $attachment = $upload_path . '/2020-RSPA-POS-Channel-KPI-Study-Update-Post-COVID.pdf';
  
          GFCommon::log_debug( __METHOD__ . '(): file to be attached: ' . $attachment );
  
  
      }
      //return altered notification object
      return $notification;
  }
  </code></pre>
  
  <p>In addition to adding an attachment to form 55, as shown in the example, I need to add a different attachment to a different form. I have changed the form ID to reflect this and copied/pasted the code into the functions file a second time, but the site breaks in doing so. The above works as expected, on it's own. How can I use the filter multiple times?</p>