- Support setting the user-agent in CronetDataSource
- Support setting the default user-agent in CronetEngineWrapper
- Use the underlying network stack's default user-agent by
default. Many applications will configure the underlying
CronetEngine or OkHttpClient with a user-agent that they
expect to be used throughout their app, so always overriding
this with our own default, on reflection, is not the best
thing to do!
Issue: #8395
PiperOrigin-RevId: 350921963
2a5f6d8f62