test(docs-infra): Correct an invalid assumption in aio tests. (#44479)

The aio application expects `FormControl` to have no properties for the purposes of its own internal tests, but this is no longer true after #44434.

PR Close #44479

aio/tests/e2e/src/api-pages.e2e-spec.ts

@@ -58,7 +58,7 @@ describe('Api pages', () => {
   });
 
   it('should not show a "Properties" section if there are only internal properties', async () => {
-    await page.navigateTo('api/forms/FormControl');
+    await page.navigateTo('api/forms/AsyncValidator');
     expect(await page.getSection('instance-properties').isPresent()).toBe(false);
   });