Document URL:

• https://docs.openshift.com/container-platform/4.8/monitoring/configuring-the-monitoring-stack.html#setting-log-levels-for-monitoring-components_configuring-the-monitoring-stack

• https://docs.openshift.com/container-platform/4.7/monitoring/configuring-the-monitoring-stack.html#setting-log-levels-for-monitoring-components_configuring-the-monitoring-stack
  Section Number and Name:
  "Setting log levels for monitoring components"

Describe the issue:
For Alertmanager the procedure only works from Openshift 4.9 and above

Suggestions for improvement:
For documentation related to Openshift below 4.9 a warning should be present to advise the procedure doesn't work for component "alertmanagerMain".