Add api_go_proto_library targets for HTTP connection manager protos.

[jmillikin-stripe]

These are required to generate xDS responses from a Go binary. If they
don't exist, implementations are required to vendor the data-plane-api
with this change applied.

Signed-off-by: John Millikin jmillikin@stripe.com

cc @kshia

[mattklein123]

@jmillikin-stripe seems fine. Can you fix tests?

[jmillikin-stripe]

OK, tests are green.

[mattklein123]

@kyessenov @htuch this keeps coming up but how can we verify this during CI? Is there any way to do it?

[kyessenov]

Perhaps, there is a way to add go_library into api macro? I haven't followed the progress on bazel front lately (once istio dropped bazel). I know it is extra difficult with gogo protobuf, so it is not worth using bazel for go-control-plane builds.

[jmillikin-stripe]

Why are we using these "api macros" instead of proto_library and go_proto_library?

[kyessenov]

proto_library needs to be weaved through cc rules which did not support native proto_library when this was written. The purpose of the api_macro was to get all three languages at once (cc, py, go).

[mattklein123]

@kyessenov I will merge this to unblock @jmillikin-stripe but can we try to figure out a way to handle this in CI? It's pretty suboptimal that this keeps happening.