With https://issues.redhat.com/browse/ENTMQST-4032 completed through the upstream https://github.com/strimzi/strimzi-kafka-operator/pull/10583 we need to add some system tests for the auto-rebalancing on scale up/down.

The applicable scenarios are:

• scaling up
• scaling down
• scaling up and, while running the rebalancing, doing another scaling up
• scaling down and, while running the rebalancing, doing another scaling down
• scaling up and, while running rebalancing, doing a scale down

Not supported scenarios:

• scaling down followed by a scaling up because when nodes are blocked during the scale down by hosting partition, there is no replicas changing from the operator point of view, so it cannot detect a scale up. The cluster is not actually changing at all.
• scaling down by deleting the node pool because no blocking mechanism kicks in, just Kubernetes garbege collection to remove pods.