title: Javax validation are not carried to Immutable generated class
body: <p>I'm using immutables.org library and want to add Javax annotation validation. But I noticed that the validations are not being carried to the generated class. I thought that immutables.org were compatible with validations annotations.
  I have <em>spring-boot-starter-validation</em> and <em>javax.validation</em> dependencies.</p>
  <p>immutable</p>
  <pre><code>@Value.Immutable
  public interface Entity {
      @Valid @Size(min = 19)
      int age();
  
      @Valid @NotBlank
      String name();
  }
  </code></pre>
  <p>Controller:</p>
  <pre><code>    @PostMapping(&quot;/entity/&quot;)
      public ResponseEntity post2(@RequestBody @Valid ImmutableEntity entity) {
  
  
          return  new ResponseEntity&lt;Object&gt;(&quot;&quot;, HttpStatus.OK);
      }
  </code></pre>
  <p>pom.xml</p>
  <pre><code>&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt;
  &lt;project xmlns=&quot;http://maven.apache.org/POM/4.0.0&quot; xmlns:xsi=&quot;http://www.w3.org/2001/XMLSchema-instance&quot;
      xsi:schemaLocation=&quot;http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd&quot;&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
      &lt;parent&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-starter-parent&lt;/artifactId&gt;
          &lt;version&gt;2.5.5&lt;/version&gt;
          &lt;relativePath/&gt; &lt;!-- lookup parent from repository --&gt;
      &lt;/parent&gt;
      &lt;groupId&gt;com.example&lt;/groupId&gt;
      &lt;artifactId&gt;testImmutable&lt;/artifactId&gt;
      &lt;version&gt;0.0.1-SNAPSHOT&lt;/version&gt;
      &lt;name&gt;testImmutable&lt;/name&gt;
      &lt;description&gt;Demo project for Spring Boot&lt;/description&gt;
      &lt;properties&gt;
          &lt;java.version&gt;1.8&lt;/java.version&gt;
      &lt;/properties&gt;
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-validation&lt;/artifactId&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-web&lt;/artifactId&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-test&lt;/artifactId&gt;
              &lt;scope&gt;test&lt;/scope&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.immutables&lt;/groupId&gt;
              &lt;artifactId&gt;value&lt;/artifactId&gt;
              &lt;version&gt;2.8.8&lt;/version&gt;
              &lt;scope&gt;provided&lt;/scope&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;javax.validation&lt;/groupId&gt;
              &lt;artifactId&gt;validation-api&lt;/artifactId&gt;
              &lt;version&gt;2.0.1.Final&lt;/version&gt;
          &lt;/dependency&gt;
          &lt;!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind --&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;com.fasterxml.jackson.core&lt;/groupId&gt;
              &lt;artifactId&gt;jackson-databind&lt;/artifactId&gt;
              &lt;version&gt;2.12.5&lt;/version&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  
      &lt;build&gt;
          &lt;plugins&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
                  &lt;artifactId&gt;spring-boot-maven-plugin&lt;/artifactId&gt;
              &lt;/plugin&gt;
          &lt;/plugins&gt;
      &lt;/build&gt;
  
  &lt;/project&gt;
  </code></pre>