title: React-Native Keystore file not set for signing config release
body: <p>I'm trying to build a release .apk file in React Native without success.
  I followed all the instructions <a href="https://facebook.github.io/react-native/docs/signed-apk-android.html" rel="noreferrer">here</a>, but i always get the same result after running <code>gradlew assembleRelease</code> in /my-project/android path:</p>
  
  <pre><code>:app:validateSigningRelease FAILED
  
  FAILURE: Build failed with an exception.
  
  * What went wrong:
  Execution failed for task ':app:validateSigningRelease'.
  &gt; Keystore file not set for signing config release
  </code></pre>
  
  <p>I'm using Windows 10 and i suspect it's something with the edit of file ~/.gradle/gradle.properties</p>
  
  <p>From my understanding ~ is c:\Users\User
  I even got a c:\Users\User.gradle folder built-in.</p>