[AMQ7] message redistribution is not possible with current cluster configuration

Message load balance is set to STRICT that effectively prevents full queue redistribution in clustered deployment[1]. Docs states that for redistribution balancing strategy should be set to ON_DEMAND[2].

The current state prevents us from testing proposed cluster scenario.

• Two broker deployed in cluster
  • Client sends messages to one node
  • Client consumes messages from another

I've 3 question to proceed with testing:

• To reach a feature parity with AMQ 6.x image the default configuration should be ON_DEMAND?
• Load balancing should be configurable with env var parameter?
• Should we change the scenario to align with STRICT strategy?

[1] https://github.com/jboss-container-images/jboss-amq-7-broker-openshift-image/blob/amq-broker-71-dev/modules/amq-launch/added/launch.sh#L152
[2] https://access.redhat.com/documentation/en-us/red_hat_amq/7.1/html/using_amq_broker/clustering#enabling_message_redistribution