title: Can't find the gradle.properties file in the react native apk instructions
body: <p>I'm following the instructions for a signed apk with react native <a href="https://facebook.github.io/react-native/docs/signed-apk-android.html" rel="noreferrer">https://facebook.github.io/react-native/docs/signed-apk-android.html</a> </p>
  
  <pre><code>MYAPP_RELEASE_STORE_FILE=my-release-key.keystore
  MYAPP_RELEASE_KEY_ALIAS=my-key-alias
  MYAPP_RELEASE_STORE_PASSWORD=*****
  MYAPP_RELEASE_KEY_PASSWORD=*****
  </code></pre>
  
  <p>However, in the step for setting up gradle variables, I can't find the <code>~/.gradle/gradle.properties</code> file on my mac.  I see a <code>~/.gradle</code> folder but I don't see the <code>gradle.properties</code> file there, should I create one?  Alternatively, I see a <code>/android/gradle.properties</code> file in my project folder - should I update the gradle variables there instead?</p>
  
  <p>Also, should I replace the <code>MYAPP</code> keyword with my app's name?  If so, where do I find the key to replace that with - is that based on some sort of setting?  e.g. <code>FOOAPP_RELEASE_STORE_FILE</code> ...</p>