[java-storage] Getting both Metadata and Content with a Single request

I might be wrong but looking at our distributed traces, it seems following code will send two GET (JSON API) requests to `stogare.googleapis.com`

```
Blob blob = storage.get(blobId);
byte[] content = blob.getContent();
```

Is there a way to get both the content and (some) metadata with a single request? There's `Storage.readAllBytes` but it does not return metadata.
We are specifically interested in `Content-Encoding`, `Content-Type` and a few other standard headers (`Cache-Control`, `Content-Length`, etc).

We have millions of small objects, and it'd be great if we can cut both the latency and the cost by half.