`interface Rpc` not exported in service definition

When I generate a service the `Rpc` interface is not exported, should it be?

```typescript
interface Rpc {
  request(service: string, method: string, data: Uint8Array): Promise<Uint8Array>;
}
```

I'm trying to implement it as a custom rpc to pass to my `ServiceClientImpl` that is generated, but since it's not exported I have to edit the file to add `export`.
