update events

enrollments-events/app/events/stopgap/set_subscription_covered.py

@@ -37,10 +37,10 @@ def lambda_handler(event: EventBridgeEvent, context: LambdaContext) -> bool:
             transact.update(
                 key=KeyPair(new_image['id'], '0'),
                 update_expr='SET subscription_covered = :subscription_covered, \
-                            updated_at = :updated_at',
+                            updated_at = :now',
                 expr_attr_values={
                     ':subscription_covered': True,
-                    ':updated_at': now_,
+                    ':now': now_,
                 },
                 cond_expr='attribute_exists(sk)',
             )