Consider splitting certain specialized tests out of garbage

Garbage was intended as a kitchen sink test, a dumping ground for stuff. But it's also gotten a bit large and difficult to understand, especially for "cross-cutting" features such as resource annotations. Consider breaking out certain features into separate tests (as the grpc service config has been separated) for better clarity. We do need to balance this against other concerns, though, e.g. separate tests will take longer to run than a combined test.