Add an install manifest to enable cgroups v1, this is to prevent an extra reboot at install time that was introduced by OCPBUGS-18640. 

apiVersion: config.openshift.io/v1
kind: Node
metadata:
  name: cluster
spec:
  cgroupMode: "v1"

This needs to be updated for 4.14 and 4.15 

    4.14, 4.15

    1.
    2.
    3.