Merge "Refactor where source builds place config files"

docker/centos/source/barbican/Dockerfile

docker/centos/source/ceilometer/ceilometer-base/Dockerfile

docker/centos/source/cinder/cinder-base/Dockerfile

docker/centos/source/designate/designate-base/Dockerfile

docker/centos/source/gnocchi/gnocchi-base/Dockerfile

docker/centos/source/heat/heat-base/Dockerfile

docker/centos/source/magnum/magnum-base/Dockerfile

docker/centos/source/murano/murano-base/Dockerfile