automatic module name for grpc-services does not match actual top level package(s)

### What version of gRPC-Java are you using?

Latest (on master)

### What did you expect to see?
automatic module name matches the top level package in the artifact

The artifact should be split into multiple artifacts to module name can be properly assigned to each artifact

### What did you see instead?
The artifact grpc-services has the following top level packages
```
io/grpc/health
io/grpc/binarylog
io/grpc/protobuf
io/grpc/services (this should be the only one)
io/grpc/channelz
io/grpc/reflection
```

### Steps to reproduce the bug
jar tvf grpc-services-1.58.0-SNAPSHOT.jar