While FFU from OSP13 to OSP16.x, the returned node of bootstrap node selection differs between puppet and ansible.

Issue

• While FFU from OSP13 to OSP16.x, the returned node of bootstrap node selection differs between puppet and ansible.
  After controller node replacement happens on the bootstrap node(the first node by dictionary order in an initial deployment),
  tripleo-ansible always returns the head node sorted by alphabetical order. On the other hand, hiera data returns the different node.
  Due to that, the bootstrap node selection in FFU guide doesn't work well in such situation.