fix(radio): update rendering and styles

PiperOrigin-RevId: 499587641

Author: asyncliz

radio/_radio.scss

@@ -1 +1,6 @@
-@forward './lib/radio-theme' show theme, theme-extension;
+//
+// Copyright 2022 Google LLC
+// SPDX-License-Identifier: Apache-2.0
+//
+
+@forward './lib/radio' show theme;