Revert "role/gerrit: single quoted string containing a variable"

${name} is gerrit magic. Puppet should not expand it, but
gerrit's replication plugin expands ${name}.

This reverts commit 6f3ed3fb0d30da4cabc95ff79513c05c2fc4d198.

Change-Id: I0a9f62c1d8cafe1694b71123ea8c78501ae30d33