title: Failed to install 'plugin.google.maps':Error: Variable(s) missing: API_KEY_FOR_ANDROID
body: <p>I have an ionic project it works fine, but when I try to run this </p>
  
  <pre><code>ionic platform add android 
  </code></pre>
  
  <p>I get this error :</p>
  
  <pre><code>Failed to install 'plugin.google.maps':Error: Variable(s) missing: API_KEY_FOR_ANDROID
      at C:\Users\RSone\AppData\Roaming\npm\node_modules\cordova\node_modules\cordova-lib\src\plugman\install.js:
  299:23
      at _fulfilled (C:\Users\RSone\AppData\Roaming\npm\node_modules\cordova\node_modules\q\q.js:787:54)
      at self.promiseDispatch.done (C:\Users\RSone\AppData\Roaming\npm\node_modules\cordova\node_modules\q\q.js:8
  16:30)
      at Promise.promise.promiseDispatch (C:\Users\RSone\AppData\Roaming\npm\node_modules\cordova\node_modules\q\
  q.js:749:13)
      at C:\Users\RSone\AppData\Roaming\npm\node_modules\cordova\node_modules\q\q.js:557:44
      at flush (C:\Users\RSone\AppData\Roaming\npm\node_modules\cordova\node_modules\q\q.js:108:17)
      at process._tickCallback (node.js:419:13)
  </code></pre>