title: Invalid api key when requesting for Google cloud Vision api in android app
body: <p>Hello I'm trying to test out the google cloud vision api for my android app.
  I enabled the api and created an OAuth 2.0 client ID and I'm using the sample code 
  from google: <a href="https://github.com/GoogleCloudPlatform/cloud-vision/blob/master/android/CloudVision/app/src/main/java/com/google/sample/cloudvision/MainActivity.java" rel="nofollow noreferrer">https://github.com/GoogleCloudPlatform/cloud-vision/blob/master/android/CloudVision/app/src/main/java/com/google/sample/cloudvision/MainActivity.java</a></p>
  
  <p>and here is the json resonse:</p>
  
  <pre><code>{"code": 400,
  
  "errors": [
  
  {
  
  "domain": "global",
  
  "message": "API key not valid. Please pass a valid API key.",
  
  "reason": "badRequest"
  
  }
  
  ],
  
  "message": "API key not valid. Please pass a valid API key.",
  
  "status": "INVALID_ARGUMENT"  }
  </code></pre>
  
  <p>I am pretty sure the api key provided is the one I am using.
  What could I be doing wrong?</p>