title: Android BuildConfig.VERSION_NAME returning null?
body: <p>I'd like to simply display my version name on my login screen, however, it's always returning null. I've defined my versionName in my app's gradle build as follows:</p>
  
  <pre><code>    defaultConfig {
      applicationId "com.maplesyrupindustries.j.airportmeet"
      minSdkVersion 19
      targetSdkVersion 24
      versionCode 7
      versionName "1.0.6"
      multiDexEnabled true
  }
  </code></pre>
  
  <p>And I am calling it in my login's onCreate:</p>
  
  <pre><code>    String build = BuildConfig.VERSION_NAME;
      Log.e(TAG, BuildConfig.VERSION_NAME);
      tvVersion.setText("Alpha " + build);
  </code></pre>
  
  <p>Yet, the build string is always empty. What gives?</p>