fix: Fixing the shutdown logic for streaming subscriber connection (#1613)

* fix: Fixing the shutdown logic for streaming subscriber connection

* fix: Fixing the shutdown logic for streaming subscriber connection

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Owl Bot 

Author: maitrimangal

google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/StreamingSubscriberConnection.java

@@ -191,15 +191,14 @@ protected void doStart() {
 
   @Override
   protected void doStop() {
-    runShutdown();
-
     lock.lock();
     try {
       clientStream.closeSendWithError(Status.CANCELLED.asException());
     } finally {
       lock.unlock();
-      notifyStopped();
     }
+    runShutdown();
+    notifyStopped();
   }
 
   private void runShutdown() {