The java client is mostly autogenerated from the relations api proto specs. In the near term, the proto specs will be managed in a central registry. When these specs change, a PR should be created with the new autogenerated code. Manual changes will likely be required for this PR.

Acceptance criteria:

1. Some hook triggers the pipeline on remote proto file changes.
2. The pipeline autogenerates the java classes and Grpc code.
3. A PR is created with those changes.