Set builder name and type to "openstack"

Set builder name and type to "openstack"

Based on the input provided on the Gihub packer issue
hard-coded for our parser to be able to decode the rest of the config
properly." This would require to hardcode the builder name and type
in the templates.

This change requires an update in global-jjb v0.60.3
and common-packer v0.7.4.

Change-Id: I9c9802356dce03a4b60e38b96d1f7e6b0e0813e5
Signed-off-by: Anil Belur <abelur@linuxfoundation.org>