dx/etc/mainDexClasses.rules

  -keep public class * extends android.app.Instrumentation {
    <init>();
  }
  -keep public class * extends android.app.Application {
    <init>();
    void attachBaseContext(android.content.Context);
  }
  -keep public class * extends android.app.backup.BackupAgent {
   <init>();
  }
# We need to keep all annotation classes because proguard does not trace annotation attribute
# it just filter the annotation attributes according to annotation classes it already kept.
  -keep public class * extends java.lang.annotation.Annotation {
   *;
  }