The source file for envoy-mesh-httproute.svg is a Google Drawing located here:

https://docs.google.com/drawings/d/1poNGeeVhSTGVBUb4AMwTccoV9I2bqTYQjMZY5LFws5s/edit?resourcekey=0-b9P5mSkTKCm1YXpxMdXdGQ