Spring boot cannot find index.html under webapp folder

I read the following documentation from spring.io and it said By default Spring Boot will serve static content from a directory called /static (or /public or /resources or /META-INF/resources) in the classpath however when I put my index.html file under /resources the string index is just rendered. Currently index.html is under webapp and I am using AngularJS.

MvcConfiguration

@Configuration
public class MvcConfig {

    @Bean
    InternalResourceViewResolver viewResolver(){

        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/webapp/");
        resolver.setSuffix(".html");

        return resolver;
    }

}

Restful Service for index page

@RestController
public class IndexController {

    @RequestMapping("/")
    public String index(){
        System.out.println("Looking in the index controller.........");
        return "index";
    }

}

ON my IDE console I do see Looking in the index controller...... printed from IndexController and under network in the Chrome development tools I only see localhost 200.

index.html

<body>

  <!--[if lt IE 7]>
      <p class="browsehappy">You are using an <strong>outdated</strong> browser. Please <a href="http://browsehappy.com/">upgrade your browser</a> to improve your experience.</p>
  <![endif]-->

  <div ng-view></div>

  <div>Angular seed app: v<span app-version></span></div>