Review Changes

- Updated the retry and max_retries of the process_ses_results celery
task to be the same as other retry strategies in that file
- Provided a message with the 200 to be similar to how other responses
are handled

app/notifications/notifications_ses_callback.py

@@ -32,7 +32,9 @@ def sns_callback_handler():
         current_app.logger.error(errors)
         raise InvalidRequest(errors, 400)
 
-    return 200
+    return jsonify(
+        result="success", message="SES callback succeeded"
+    ), 200
 
 
 def process_ses_response(ses_request):