1. Proposed title of this feature request

Allow editing balanceSimilarNodeGroups value in ClusterAutoscaler resource for ROSA

2. What is the nature and description of the request?

Testing Environement:

ROSA 4.10.10   &   ARO 4.9.28

1) create a new namespace test => oc new-project test

2) create a new deployment => oc new-app --docker-image=docker.io/openshift/hello-openshift -n test

3) scale up the application => oc scale --replicas=20 deploy hello-openshift -n test

Ran "oc get machinesets -A":

NAMESPACE                      NAME                                                                    DESIRED    CURRENT 

openshift-machine-api    nsutestaro-5hdcr-worker-southeastasia               1                  1

openshift-machine-api    nsutestaro-5hdcr-worker-southeastasia               1                  1                                                                                     

openshift-machine-api     nsutestaro-5hdcr-worker-southeastasia              6                  6

But with "balanceSimilarNodeGroups: true" set in the CRD ClusterAutoScaler in ARO, the distribution was quite balance as below:

NAMESPACE                      NAME                                                                    DESIRED    CURRENT 

openshift-machine-api    nsutestaro-5hdcr-worker-southeastasia               3                 3

openshift-machine-api    nsutestaro-5hdcr-worker-southeastasia               3                 3                                                                                         

openshift-machine-api     nsutestaro-5hdcr-worker-southeastasia              2                 2

Based on the below KCS, the config is needed to balance node allocation:

https://access.redhat.com/solutions/4837091

however, admins are not allowed to modify the CRD on ROSA, get denied as below:

~~~~~~~~~~~~~~~

error: clusterautoscalers.autoscaling.openshift.io "default" could not be patched: admission webhook "regular-user-validation.managed.openshift.io" denied the request: Prevented from accessing Red Hat managed resources. This is in an effort to prevent harmful actions that may cause unintended consequences or affect the stability of the cluster. If you have any questions about this, please reach out to Red Hat support at https://access.redhat.com/support

~~~~~~~~~~~~~~~

3. Why does the customer need this? (List the business requirements here)

To be able to balance nodes to machinesets as expected.

4. List any affected packages or components.

Machineset