gRPC-netty is old, and depends on a broken version of netty

I'm trying to use Dagger-gRPC which is, as far as I understand, built with dependencies coming from this repository - specifically grpc-netty (dependency defined [here](https://github.com/google/dagger/blob/master/java/dagger/grpc/server/BUILD#L43)).

The issue is, the grpc-netty version pulled in by bazel-common is quite old: [it's the 1.2.0](https://github.com/google/bazel-common/blob/master/workspace_defs.bzl#L232), released in early 2017. It pulls in `io.netty:netty-codec-http2:4.1.8.Final`, which has a bug (described [here](https://github.com/grpc/grpc-java/issues/3056), fixed in early 2017 too).

Would it be possible to update the gRPC version pulled in by this repo?