YARN-9197. Add safe guard against NPE for component instance failure.

            Contributed by kyungwan nam

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/main/java/org/apache/hadoop/yarn/service/component/instance/ComponentInstance.java

@@ -350,8 +350,10 @@ public class ComponentInstance implements EventHandler<ComponentInstanceEvent>,
         // record in ATS
         LOG.info("Publishing component instance status {} {} ",
             event.getContainerId(), containerState);
+        int exitStatus = failureBeforeLaunch || event.getStatus() == null ?
+            ContainerExitStatus.INVALID : event.getStatus().getExitStatus();
         compInstance.serviceTimelinePublisher.componentInstanceFinished(
-            event.getContainerId(), event.getStatus().getExitStatus(),
+            event.getContainerId(), exitStatus,
             containerState, containerDiag);
       }
 
@@ -366,8 +368,10 @@ public class ComponentInstance implements EventHandler<ComponentInstanceEvent>,
 
       if (compInstance.timelineServiceEnabled) {
         // record in ATS
+        int exitStatus = failureBeforeLaunch || event.getStatus() == null ?
+            ContainerExitStatus.INVALID : event.getStatus().getExitStatus();
         compInstance.serviceTimelinePublisher.componentInstanceFinished(
-            event.getContainerId(), event.getStatus().getExitStatus(),
+            event.getContainerId(), exitStatus,
             containerState, containerDiag);
       }