title: Warning causing android build to fail
body: <p>I have native android code that i bundle with my app. This has always been working for many months. But today, the same code is failing with warnings. I think the last successful build was two days ago:</p>
  
  <pre><code>--    
  Note: there were 5 references to unknown classes.
            You should check your configuration for typos.
            (http://proguard.sourceforge.net/manual/troubleshooting.html#unknownclass)
      Note: there were 1927 unkept descriptor classes in kept class members.
            You should consider explicitly keeping the mentioned classes
            (using '-keep').
            (http://proguard.sourceforge.net/manual/troubleshooting.html#descriptorclass)
      Note: there were 2 unresolved dynamic references to classes or interfaces.
            You should check if you need to specify additional program jars.
            (http://proguard.sourceforge.net/manual/troubleshooting.html#dynamicalclass)
      Note: there were 4 class casts of dynamically created class instances.
            You might consider explicitly keeping the mentioned classes and/or
            their implementations (using '-keep').
            (http://proguard.sourceforge.net/manual/troubleshooting.html#dynamicalclasscast)
      Warning: there were 23 unresolved references to program class members.
               Your input classes appear to be inconsistent.
               You may need to recompile the code.
               (http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedprogramclassmember)
      Exception while processing task 
      java.io.IOException: Please correct the above warnings first.
          at proguard.Initializer.execute(Initializer.java:473)
          at proguard.ProGuard.initialize(ProGuard.java:233)
          at proguard.ProGuard.execute(ProGuard.java:98)
          at proguard.gradle.ProGuardTask.proguard(ProGuardTask.java:1074)
          at com.android.build.gradle.tasks.AndroidProGuardTask.doMinification(AndroidProGuardTask.java:139)
          at com.android.build.gradle.tasks.AndroidProGuardTask$1.run(AndroidProGuardTask.java:115)
          at com.android.builder.tasks.Job.runTask(Job.java:48)
          at com.android.build.gradle.tasks.SimpleWorkQueue$EmptyThreadContext.runTask(SimpleWorkQueue.java:41)
          at com.android.builder.tasks.WorkQueue.run(WorkQueue.java:227)
          at java.lang.Thread.run(Thread.java:745)
      :proguardRelease (Thread[Daemon worker,5,main]) completed. Took 6.197 secs.
      :dexRelease (Thread[Daemon worker,5,main]) started.
      :dexRelease
      Executing task ':dexRelease' (up-to-date check took 0.058 secs) due to:
  ---
  </code></pre>