storage: Fix lease transfer metric names
storage: Fix lease transfer metric names

This will require updating our grafana graphs, but it doesn't look like
the admin UI uses these yet.

paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach