message: Fix JNI after minification is applied
  UbershaderProvider.getNativeObject() is accessed from AssetLoader.cpp,
  so it must be annotated with to
  avoid runtime crashes when minification is applied.
  Fixes
diff: @@ -20,6 +20,7 @@ import com.google.android.filament.Engine;
  import com.google.android.filament.MaterialInstance;
  import com.google.android.filament.Material;
  import com.google.android.filament.VertexBuffer;
  +import com.google.android.filament.proguard.UsedByNative;
  import androidx.annotation.NonNull;
  import androidx.annotation.Nullable;
  @@ -94,6 +95,7 @@ public class UbershaderProvider implements MaterialProvider {
  nDestroyMaterials(mNativeObject);
  }
  + @UsedByNative("AssetLoader.cpp")
  public long getNativeObject() {
  return mNativeObject;
  }
  