style(docs-infra): fix docs examples for tslint rule semicolon (#38143)

This commit updates the docs examples to be compatible with the
`semicolon` 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/src/app/request-cache.service.ts

@@ -12,7 +12,7 @@ export interface RequestCacheEntry {
 // #docregion request-cache
 export abstract class RequestCache {
   abstract get(req: HttpRequest<any>): HttpResponse<any> | undefined;
-  abstract put(req: HttpRequest<any>, response: HttpResponse<any>): void
+  abstract put(req: HttpRequest<any>, response: HttpResponse<any>): void;
 }
 // #enddocregion request-cache