Use Authorizer.

Signed-off-by: Lantao Liu <lantaol@google.com>

pkg/server/image_pull.go

@@ -261,7 +261,7 @@ func (c *criService) getResolver(ctx context.Context, ref string, cred func(stri
 			return nil, imagespec.Descriptor{}, errors.Wrapf(err, "parse registry endpoint %q", e)
 		}
 		resolver := docker.NewResolver(docker.ResolverOptions{
-			Credentials: cred,
+			Authorizer: docker.NewAuthorizer(http.DefaultClient, cred),
 			Client:     http.DefaultClient,
 			Host:       func(string) (string, error) { return u.Host, nil },
 			// By default use "https".