title: Running Vendor Test Suite(VTS) on Android 8.1
body: <p>I'm trying to experiment VTS on my phone Pixel by following the VTS manual provided by Google. It keeps displaying the error: </p>
  
  <pre><code>E/VtsVendorConfigFileUtil: Vendor test config file /config/vts-tradefed-vendor-config-prod.json does not exist
  </code></pre>
  
  <p>I tried to built both on branch master and branch m/android-8.1.0_r1, and both failed. My phone has version Android 8.1.1.</p>
  
  <p>Does anyone have any idea to resolve this issue? </p>