[RHOCP 4] Missing search domain in '/etc/resolv.conf' on OpenShift nodes

Issue

• The search domain was missing in/etc/resolv.conf across all nodes of the RHOCP v4.9.31 cluster installed on the OpenStack platform with IPI installation.

• RHOCP v4.9.31 cluster did not have the search domain in /etc/resolv.conf, which was there in the RHOCP v4.8 cluster:

  OpenShift v4.9.31
  sh-4.4# cat /etc/resolv.conf 
  # Generated by KNI resolv prepender NM dispatcher script
  nameserver 172.xx.xx.xx
  nameserver 10.xx.xx.xx
  nameserver 10.xx.xx.xx
  
  OpenShift v4.8.29
  # Generated by KNI resolv prepender NM dispatcher script
  search   hostname.lab.example.com
  nameserver 172.xx.xx.xx
  nameserver 10.xx.xx.xx
  nameserver 10.xx.xx.xx