title: ConfigurationProperties for final fields doesn't work
body: <p>I need to set data from <code>application.yml</code> file to my config class but when I trying to do it I get an error:</p>
  <pre><code>TestConfig is annotated with @ConstructorBinding but it is defined as a regular bean which caused dependency injection to fail.
  </code></pre>
  <p>My <code>application.yml</code> file looks like the following:</p>
  <pre><code>test:
    app:
      id: app_id
  
  </code></pre>
  <p>My <code>TestConfig</code> class looks like this:</p>
  <pre><code>@Configuration
  @ConfigurationProperties(prefix = &quot;test.app&quot;)
  @ConstructorBinding
  public class TestConfig {
      private final String id;
  
      public TestConfig(String id) {
          this.id = id;
      }
  }
  </code></pre>
  <p>I'm trying to do like <a href="https://docs.spring.io/spring-boot/docs/2.4.0/reference/html/appendix-configuration-metadata.html#configuration-metadata-annotation-processor" rel="nofollow noreferrer">this</a> but it doesn't work for me.<br/>
  Where I was wrong?</p>