Updates overcloud-resource-registry.j2.yaml to include the mappings from
enviornments/config-download-environment.yaml. This enables
config-download by default. The environment to explicitly enable
config-download is deprecated.
An environment at environments/disable-config-download.yaml is added
which can be used to disable config-download but is marked as
deprecated.
Change-Id: I8389a0c48e1aa610fdc6a8580516889340883034
implements: blueprint config-download-default