chore: add ObjectExistsWithSize to respect the interface

new method was added in grafana#14268

pkg/storage/chunk/client/gcp/gcs_thanos_object_client.go

@@ -72,6 +72,21 @@ func (s *GCSThanosObjectClient) ObjectExists(ctx context.Context, objectKey stri
 	return s.client.Exists(ctx, objectKey)
 }
 
+// ObjectExistsWithSize checks if a given objectKey exists and it's size in the GCS bucket
+func (s *GCSThanosObjectClient) ObjectExistsWithSize(ctx context.Context, objectKey string) (bool, int64, error) {
+	_, err := s.client.Get(ctx, objectKey)
+	if err != nil {
+		return false, 0, err
+	}
+
+	attr, err := s.client.Attributes(ctx, objectKey)
+	if err != nil {
+		return true, 0, nil
+	}
+
+	return true, attr.Size, nil
+}
+
 // PutObject puts the specified bytes into the configured GCS bucket at the provided key
 func (s *GCSThanosObjectClient) PutObject(ctx context.Context, objectKey string, object io.Reader) error {
 	return s.client.Upload(ctx, objectKey, object)