Fix useId tests

TODO: investigate why we can't update snapshots

Author: eps1lon

packages/react-dom/src/__tests__/ReactDOMUseId-test.js

@@ -37,6 +37,7 @@ describe('useId', () => {
     useState = React.useState;
 
     container = document.createElement('div');
+    container.setAttribute('id', 'container');
     document.body.appendChild(container);
 
     buffer = '';