fix(storage): close HTTP2 response bodies to prevent flow-control leaks

[krishnamd-jkp]

Fixes an issue where HTTP2 stream connections might exhaust flow-control quota and cause INTERNAL_ERROR in long-lived connections.

• Modifies httpReader.Read to properly close the previous stream body before reopening it.
• Adds a defer block in parseReadResponse to ensure response bodies aren't leaked when an error is returned during header parsing.
• Ensures bodies are closed when stream discarding (io.CopyN) or X-Goog-Generation header parsing fails in readerReopen. These fixes apply equally to both the JSON and XML reader code paths.

[gemini-code-assist]

Code Review

This pull request improves resource management in storage/http_client.go by ensuring http.Response.Body is consistently closed during error conditions and before retrying read operations. Key changes include moving the body closure before reopening connections in the Read method and implementing a deferred closure in parseReadResponse using named return parameters. Feedback suggests enhancing error context in parseReadResponse by wrapping the strconv.ParseInt error when handling invalid Content-Range headers.

[gemini-code-assist]

The error from strconv.ParseInt is discarded here. Per repository rules, helper functions that parse strings should include error handling for parsing failures. For consistency and better error context, consider wrapping the error here as well.

Suggested change

	err = fmt.Errorf("storage: invalid Content-Range %q", cr)
	return nil, err
	err = fmt.Errorf("storage: invalid Content-Range %q: %w", cr, err)
	return nil, err

References

1. When implementing helper functions that parse strings, always include error handling for parsing failures.

[cpriti-os]

Fix this?