refactor(docs-infra): fix docs examples for tslint rules related to variable names (#38143)

This commit updates the docs examples to be compatible with the
`no-shadowed-variable` and `variable-name` tslint rules.

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/src/app/request-cache.service.ts

@@ -44,8 +44,8 @@ export class RequestCacheWithMap implements RequestCache {
     const url = req.urlWithParams;
     this.messenger.add(`Caching response from "${url}".`);
 
-    const entry = { url, response, lastRead: Date.now() };
-    this.cache.set(url, entry);
+    const newEntry = { url, response, lastRead: Date.now() };
+    this.cache.set(url, newEntry);
 
     // remove expired cache entries
     const expired = Date.now() - maxAge;

aio/content/examples/http/src/testing/http-client.spec.ts

@@ -83,7 +83,7 @@ describe('HttpClient testing', () => {
     // #docregion predicate
     // Expect one request with an authorization header
     const req = httpTestingController.expectOne(
-      req => req.headers.has('Authorization')
+      request => request.headers.has('Authorization')
     );
     // #enddocregion predicate
     req.flush(testData);