Move coordinated-shutdown config from test/resources, #23879

* looks like the ActorSystem is shutdown when leaving
* Included in MultiNodeSpec, i.e. all multi-node tests:
  akka.coordinated-shutdown.terminate-actor-system = off
  akka.oordinated-shutdown.run-by-jvm-shutdown-hook = off

akka-cluster/src/multi-jvm/scala/akka/cluster/MultiNodeClusterSpec.scala

@@ -46,6 +46,8 @@ object MultiNodeClusterSpec {
       periodic-tasks-initial-delay        = 300 ms
       publish-stats-interval              = 0 s # always, when it happens
       failure-detector.heartbeat-interval = 500 ms
+
+      run-coordinated-shutdown-when-down = off
     }
     akka.loglevel = INFO
     akka.log-dead-letters = off