title: ansible handler not found when used when included as play within pre_tasks
body: <p>In my pre_task of master playbook(site.yml), 
  I have included one of the playbooks from a my_role 
  (located in my_role/tasks/my_playbook)</p>
  
  <p>This my_playbook calls a handler, which is located in the role directory(my_role/handlers/main.yml)
  and I am getting handler not found error. </p>
  
  <p>What are the types I can use inside the pre_task??</p>