AdaptiveCards/main/samples/v1.5/Scenarios/Agenda.json car.png points at old CDN

AdaptiveCards/main/samples/v1.5/Scenarios/Agenda.json is out of date.  One of the URLs points at the old cdn

In the card
<https://cdn.adaptivecards.io/assets/car.png>
should be
<https://adaptivecards.io/content/car.png>

as it is shown on this page
<https://adaptivecards.io/samples/Agenda.html>