Empty node-sizing SYSTEM_RESERVED_ES parameter can result in kubelet not starting in OpenShift Container Platform 4

Issue

• After upgrading to RHOCP 4.11.17 or 4.10.43, nodes got stuck in NotReady state, showing the below kubelet error message:

  Dec 07 12:38:46 cp-node-01 hyperkube[100739]: Error: failed to run Kubelet: quantities must match the regular expression '^([+-]?[0-9.]+)([eEinumkKMGTP]*[-+]?[0-9]*)$'
  Dec 07 12:38:46 cp-node-01 systemd[1]: kubelet.service: Failed with result 'exit-code'.
  Dec 07 12:38:46 cp-node-01 systemd[1]: Failed to start Kubernetes Kubelet.
  

• After upgrading to RHOCP 4.11.17or 4.10.43 experienced an issue whereby /etc/node-sizing.env on its master nodes contained an empty SYSTEM_RESERVED_ES value.