title: How to set sourceCompatability to javaVersion.VERSION_1_8
body: <p>I installed jdk1.8.0_112 and write code below in build.gradle</p>
  
  <pre><code> compileOptions {
          sourceCompatibility JavaVersion.VERSION_1_8
          targetCompatibility JavaVersion.VERSION_1_8
      }
  </code></pre>
  
  <p>i received this error</p>
  
  <pre><code>Error:Jack is required to support java 8 language features. Either enable Jack or remove sourceCompatibility JavaVersion.VERSION_1_8.
  </code></pre>
  
  <p>Can anyone help me?</p>