DeviceActorMessageProcessor(AbstractContextAwareMsgProcessor): ObjectMapper live instance count reduced with a static ObjectMapper

application/src/main/java/org/thingsboard/server/actors/shared/AbstractContextAwareMsgProcessor.java

@@ -22,13 +22,13 @@ import org.thingsboard.server.actors.TbActorCtx;
 import org.thingsboard.server.common.msg.TbActorMsg;
 
 import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
 
 @Slf4j
 public abstract class AbstractContextAwareMsgProcessor {
 
+    protected final static ObjectMapper mapper = new ObjectMapper();
+
     protected final ActorSystemContext systemContext;
-    protected final ObjectMapper mapper = new ObjectMapper();
 
     protected AbstractContextAwareMsgProcessor(ActorSystemContext systemContext) {
         super();