refactor(docs-infra): fix docs examples for tslint rule only-arrow-functions (#38143)

This commit updates the docs examples to be compatible with the
`only-arrow-functions` tslint rule.

This is in preparation of updating the docs examples `tslint.json` to
match the one generated for new Angular CLI apps in a future commit.

PR Close #38143

aio/content/examples/http/e2e/src/app.e2e-spec.ts

@@ -28,7 +28,7 @@ let checkLogForMessage = (message: string) => {
   expect(page.logList.getText()).toContain(message);
 };
 
-describe('Http Tests', function() {
+describe('Http Tests', () => {
   beforeEach(() => {
     browser.get('');
   });