title: WARNING: API 'variant.getMappingFile()' is obsolete and has been replaced with 'variant.getMappingFileProvider()'
body: <p>I just updated Android Studio 3.5 to Android Studio 3.6 and replaced previous Gradle plugin with Gradle plugin 3.6.0 when syncing Gradle:</p>
  
  <blockquote>
    <p>build.gradle: API 'variant.getMappingFile()' is obsolete and has been
    replaced with 'variant.getMappingFileProvider()'</p>
  </blockquote>
  
  <p>Any suggestions on how to debug this warning. Where is it coming from? I don't see any usage of getMappingFile in my code although, might be some library. Suggestions to debug these kind of cases would be helpful </p>