Log beat signals for xray integration testing (#2263)

Co-authored-by: Mike Pond <[email protected]>

app/celery/celery.py

@@ -56,7 +56,8 @@ def init_app(self, app):
             signals.task_failure.connect(xray_task_failure)
             signals.task_postrun.connect(xray_task_postrun)
             signals.task_prerun.connect(xray_task_prerun)
-            signals.beat_init.connect(xray_task_prerun)
+            signals.beat_init.connect(lambda: app.logger.info("Celery beat signal intercepted"))
+            signals.beat_embedded_init.connect(lambda: app.logger.info("Celery embedded beat signal intercepted"))
 
         # See https://docs.celeryproject.org/en/stable/userguide/configuration.html
         self.conf.update(