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

This commit updates the docs examples to be compatible with the
`import-spacing` 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/user-input/src/app/app.component.ts

@@ -1,5 +1,5 @@
 // #docregion
-import { Component }           from '@angular/core';
+import { Component } from '@angular/core';
 
 @Component({
   selector: 'app-root',

aio/content/examples/user-input/src/app/app.module.ts

@@ -1,5 +1,5 @@
 import { NgModule } from '@angular/core';
-import { BrowserModule }  from '@angular/platform-browser';
+import { BrowserModule } from '@angular/platform-browser';
 
 import { AppComponent } from './app.component';
 import { ClickMeComponent } from './click-me.component';