add config-item for MNA to disable downgrade

Author: demonCoder95

cluster/config-defaults.yaml

@@ -1202,6 +1202,13 @@ kube_janitor_enabled: "true"
 teapot_admission_controller_scheduling_controls_enabled: "false"
 teapot_admission_controller_scheduling_controls_default_architecture: "amd64"
 
+# master-node-autoscaler configuration
+
+# Ignore recommendations for downgrading the instance generation of the master nodes
+# This is required to persist the upgrade of instance generation for master nodes
+# in a cluster.
+master_node_autoscaler_instance_downgrade_disabled: "false"
+
 # role-sync-controller configs
 # Enabled by default only on Zalando EKS clusters
 {{ if eq .Cluster.Provider "zalando-eks" }}