message: Render, then update the CSS in the `MenuItem`
diff: @@ -23,8 +23,8 @@ export class MenuItem extends ThemeableElementBase {
  constructor() {
  super();
  this.attachShadow({ mode: "open", delegatesFocus: false });
  - this.updateThemeCss();
  this._render();
  + this.updateThemeCss();
  }
  @Attribute({default: false}) selected: boolean;
  