Fix some of the string-substitution magic in the labs vm build.

Puppet certs use the instance-id name rather than the human-readable
name.  Previously this regexp was looking for the human-readable fqdn,
and not finding it.  So...

"How did this ever work?"

Change-Id: I94098dfdd3da80634008bc2dc6dde346a4df409a
Merge "Fix some of the string-substitution magic in the labs vm build." into production