Cronvoy: testing - support induced errors through Envoy Mobile filter

The Cronet [MockUrlRequestJobFactory](https://source.chromium.org/chromium/chromium/src/+/main:components/cronet/android/test/src/org/chromium/net/MockUrlRequestJobFactory.java) must be properly ported, and this involves a mechanism to set the induced error, likely with the help of an Envoy Mobile Filter