Cleanup some include logic

* Properly mark hosts with failures in includes as failed
* Don't send callbacks until we're sure we're done, and also fix how
  we increment stats so failures don't show up as ok's
* Fix a bug in the include file logic where a failed include could lead
  to an infinite loop in the task iteration logic

Fixes #12933

lib/ansible/executor/play_iterator.py

@@ -396,6 +396,9 @@ class PlayIterator:
         return None
 
     def _insert_tasks_into_state(self, state, task_list):
+        if state.fail_state != self.FAILED_NONE:
+            return state
+
         if state.run_state == self.ITERATING_TASKS:
             if state.tasks_child_state:
                 state.tasks_child_state = self._insert_tasks_into_state(state.tasks_child_state, task_list)