Don't ensure pki permissions for releases <= Pike

Openstack PKI token support was dropped in the Pike release.
The following update ensures that PKI token validation is
only run if the release is supported when the sync leader
broadcasts any service credentials to its peers.

In this case; if the release is <= pike. then we can sync
token certs and ensure the pki permissions are valid.
Otherwise this action will be skipped.

Closes-Bug: 1759403
Change-Id: I3d8ba6d3cac3a3505a3722a5082c3a6933a9ef67