title: Use rear facing dual camera in Android
body: <p>I'm trying to capture using both of the rear facing cameras on my xiaomi mi 5s plus.
  When I'm trying to iterate through the id's of the cameras using camera2 api, I only get 2 id's, one for the front facing camera and one for the rear one.
  I've looked in the lg development examples (<a href="http://mobile.developer.lge.com/develop/sdks/lg-dual-camera/" rel="noreferrer">http://mobile.developer.lge.com/develop/sdks/lg-dual-camera/</a>) and they are using 3 ids. When running their example, the app crashes.</p>
  
  <p>The code used for getting the ids is:</p>
  
  <pre><code>CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
  for(String id: manager.getCameraIdList())
      Log.e("test", id);
  </code></pre>