title: Proguard dontwarn command for duplicate zip entry?
body: <p>After migration to AndroidX proguard fails with:</p>
  <pre><code>EXEC : warning : Exception while processing task java.io.IOException: Can't write [B:\Bamboo-build-dir\PGP-ALLPLATFORMS-JOB1\build\android\build\intermediates\transforms\proguard\Google\release\0.jar] (Can't read [C:\Users\buildsrv\.gradle\caches\transforms-1\files-1.1\support-compat-26.1.0.aar\6973853fc6cf653ca71c47008b82982d\jars\classes.jar(;;;;;;**.class)] (Duplicate zip entry [android/support/v4/c/c$a.class == classes.jar:android/support/v4/os/ResultReceiver$MyResultReceiver.class])) 
  </code></pre>
  <p>How do I disable this warning with <code>dontwarn</code> ?</p>