OBSDOCS-1492: [DOC] Early validation for monitoring configmaps

Author: eromanova97

observability/monitoring/config-map-reference-for-the-cluster-monitoring-operator.adoc

@@ -32,7 +32,7 @@ Only the parameters and fields listed in this reference are supported for config
 For more information about supported configurations, see xref:../monitoring/configuring-the-monitoring-stack.adoc#maintenance-and-support_configuring-the-monitoring-stack[Maintenance and support for monitoring].
 * Configuring cluster monitoring is optional.
 * If a configuration does not exist or is empty, default values are used.
-* If the configuration is invalid YAML data, the Cluster Monitoring Operator stops reconciling the resources and reports `Degraded=True` in the status conditions of the Operator.
+* If the configuration has invalid YAML data, or if it contains unsupported or duplicated fields that bypassed early validation, the Cluster Monitoring Operator stops reconciling the resources and reports the `Degraded=True` status in the status conditions of the Operator.
 ====
 
 == AdditionalAlertmanagerConfig