title: INVALID_KEY message trying to authenticate through the Google+ Sign in Button
body: <p>I am trying to authenticate the user following <a href="https://gist.github.com/ianbarber/5170508">this gist by Ian Barber</a>. The button asks for the user account, but it never gets to show the authorization dialog and instead exits with the message "An internal error ocurred". Logcat shows this: </p>
  
  <pre><code>W/GLSUser ( 4353): Status from wire: INVALID_KEY status: null
  W/GLSUser ( 4353): Status from wire: INVALID_KEY status: null
  E/GLSUser ( 4353): Empty consent data
  I/GLSUser ( 4353): GLS error: INVALID_KEY icoloma@gmail.com oauth2:https://www.googleapis.com/auth/plus.login
  W/GLSUser ( 4353): Status from wire: Unknown status: UNKNOWN
  </code></pre>
  
  <p>The certificate used to sign my app is the same configured at my Google API Console page, and the package name is also the same. </p>