Purchase event triggered on canceled order.

[JoostWan]

1. Place an order using a payment method such as iDeal through Multisafepay.
2. Cancel the payment on the bank's page; you will be redirected back to the shop with the cart intact.
3. At this moment, the purchase event is triggered on the event sales_order_place_after.

The order state is, at that moment, pending_payment, and a few seconds later, it will be set to canceled.

https://github.com/yireo/Yireo_GoogleTagManager2/blob/master/etc/frontend/events.xml#L32

Is it possible to show the purchase tag/event only on the checkout_onepage_success page.