WW-4553 Merges #55 which moves creation of interceptors list and iterator to a factory method to allow overriding it

core/src/main/java/com/opensymphony/xwork2/DefaultActionInvocation.java

@@ -396,7 +396,11 @@ public class DefaultActionInvocation implements ActionInvocation {
         invocationContext = new ActionContext(contextMap);
         invocationContext.setName(proxy.getActionName());
 
-        // get a new List so we don't get problems with the iterator if someone changes the list
+        createInterceptors(proxy);
+    }
+
+    protected void createInterceptors(ActionProxy proxy) {
+        // Get a new List so we don't get problems with the iterator if someone changes the original list
         List<InterceptorMapping> interceptorList = new ArrayList<>(proxy.getConfig().getInterceptors());
         interceptors = interceptorList.iterator();
     }