Revert "CONTRIB-9626 remove unused property from action_link"

This reverts commit e28c2fb.

renderable.php

@@ -348,6 +348,7 @@ public function action_link(moodle_url $url, $titlekey, $iconkey, $confirmkey =
             $confirmaction = new confirm_action(get_string($confirmkey, 'scheduler'));
         }
         $act = new action_link($url, $title, $confirmaction, $attributes, $pix);
+        $act->primary = false;
         return $act;
     }