title: 'Failed to transform" error after migrating to AndroidX
body: <p>I'm using Android Studio 3.2 Canary 14 and am trying to migrate an existing project to use <code>AndroidX</code>. It sounds from <a href="https://developer.android.com/topic/libraries/support-library/androidx-rn" rel="noreferrer">https://developer.android.com/topic/libraries/support-library/androidx-rn</a> that I have to have set <code>android.enableJetifier=true</code> (this was done automatically for me when selecting "Refactor to AndroidX.." option). I've also updated target API level to 28.  Anyone else seeing this issue?</p>
  
  <blockquote>
    <p>Failed to transform
    '/Users/jooreill/.gradle/caches/modules-2/files-2.1/com.google.firebase/firebase-perf/15.0.0/6e68f6e44b0c9d91756f903547ee3853349ae666/firebase-perf-15.0.0.aar' using Jetifier. Reason: null. (Run with --stacktrace for more
    details.) To disable Jetifier, set android.enableJetifier=false in
    your gradle.properties file.</p>
  </blockquote>
  
  <p>The above error occurs when I run "Clean".  In general am getting multiple errors like following if a do gradle sync:</p>
  
  <blockquote>
    <p>Unable to resolve dependency for
    ':app-instant@debug/compileClasspath': Failed to transform file
    'play-services-measurement-base-15.0.2.aar' to match attributes
    {artifactType=jetified-aar} using transform JetifyTransform</p>
  </blockquote>