heat common : context should split roles from X-Roles
heat common : context should split roles from X-Roles

The auth_token code joins roles with a comma delimiter and stores
the result in the X-Roles header, so we need to split X-Roles back
into a list for the context (otherwise the oslo policy code breaks)

Change-Id: I32bd1d6355b6fe0e16e729f35b1d0b5c61346a70
Signed-off-by: Steven Hardy <4d1810d1ff6d7f22d774341c4549c02173d2f2ab@redhat.com>

miguelgrinberg/heat,pratikmallya/heat,dims/heat,ntt-sic/heat,citrix-openstack-build/heat,pshchelo/heat,noironetworks/heat,NeCTAR-RC/heat,steveb/heat,Triv90/Heat,rh-s/heat,srznew/heat,ntt-sic/heat,redhat-openstack/heat,noironetworks/heat,maestro-hybrid-cloud/heat,takeshineshiro/heat,jasondunsmore/heat,openstack/heat,openstack/heat,gonzolino/heat,JioCloud/heat,cwolferh/heat-scratch,cwolferh/heat-scratch,dims/heat,maestro-hybrid-cloud/heat,gonzolino/heat,cryptickp/heat,rdo-management/heat,takeshineshiro/heat,rdo-management/heat,rickerc/heat_audit,JioCloud/heat,Triv90/Heat,jasondunsmore/heat,miguelgrinberg/heat,srznew/heat,varunarya10/heat,pratikmallya/heat,NeCTAR-RC/heat,rickerc/heat_audit,redhat-openstack/heat,Triv90/Heat,steveb/heat,citrix-openstack-build/heat,pshchelo/heat,varunarya10/heat,rh-s/heat,dragorosson/heat,dragorosson/heat,cryptickp/heat