Compared to KubeRay v1.2.0, KubeRay v1.2.1 includes an additional commit (#2243). This commit fixes the issue where a RayService created by a KubeRay version older than v1.2.0 does not support zero-downtime upgrades after upgrading to KubeRay v1.2.0.

• [RayService] Use original ClusterIP for new head service (#2343, @kevin85421)