add logging of OOM of not PID1 processes in docker containers (#1135)

Signed-off-by: Alexander Garagatyi <agaragatyi@codenvy.com>

plugins/plugin-docker/che-plugin-docker-machine/src/main/java/org/eclipse/che/plugin/docker/machine/DockerInstanceStopDetector.java

@@ -122,6 +122,7 @@ public class DockerInstanceStopDetector {
             switch (message.getStatus()) {
                 case "oom":
                     containersOomTimestamps.put(message.getId(), message.getId());
+                    LOG.info("OOM of process in container {} has been detected", message.getId());
                     break;
                 case "die":
                     InstanceStateEvent.Type instanceStateChangeType;