Missing CesiumMilkTruck.dae for export KML Sandcastle

[OmarShehata]

The export KML Sandcastle needs to be able to reference CesiumMilkTruck.dae to download it instead of the glTF in the exported KMZ. This works fine in 1.67, but in 1.68 you'll get a 404 for this model.

Here's the deployed Sandcastle for master:

http://cesium-dev.s3-website-us-east-1.amazonaws.com/cesium/master/Apps/Sandcastle/index.html?src=Export%20KML.html

This file is supported to be here: https://github.com/CesiumGS/cesium/tree/master/Apps/SampleData/models/CesiumMilkTruck. But I can't seem to find it even when going back through the git history. Here's that folder in 1.67 and it's not there:

https://github.com/CesiumGS/cesium/tree/1.67/Apps/SampleData/models/CesiumMilkTruck

Which doesn't make sense.

@sanjeetsuhag was this removed when you were optimizing models?

[mramato]

Dupe of #8510 This is an easy fix, no idea why no one has done it yet.

[OmarShehata]

Ah, thanks @mramato . It still works likely because of how our deployment process doesn't delete files. I'll just fix this now.

[sanjeetsuhag]

@OmarShehata No, it was removed in 1.63