Clean up metadata refresh unit test
Clean up metadata refresh unit test

The stack was not being fully created, because the calls to the mock
functions were not present for the second instance.

Change-Id: I894473533eb40133e4c22facbbee749a971cec89

miguelgrinberg/heat,pratikmallya/heat,steveb/heat,varunarya10/heat,maestro-hybrid-cloud/heat,pshchelo/heat,ntt-sic/heat,rh-s/heat,cwolferh/heat-scratch,redhat-openstack/heat,cryptickp/heat,dims/heat,openstack/heat,noironetworks/heat,rickerc/heat_audit,citrix-openstack-build/heat,dragorosson/heat,dims/heat,rickerc/heat_audit,gonzolino/heat,rdo-management/heat,maestro-hybrid-cloud/heat,varunarya10/heat,openstack/heat,takeshineshiro/heat,miguelgrinberg/heat,pratikmallya/heat,takeshineshiro/heat,jasondunsmore/heat,cryptickp/heat,redhat-openstack/heat,pshchelo/heat,dragorosson/heat,steveb/heat,gonzolino/heat,srznew/heat,citrix-openstack-build/heat,NeCTAR-RC/heat,srznew/heat,NeCTAR-RC/heat,rdo-management/heat,cwolferh/heat-scratch,jasondunsmore/heat,noironetworks/heat,JioCloud/heat,JioCloud/heat,ntt-sic/heat,rh-s/heat