code: public void loadModel(GVRAndroidResource avatarResource)
      {
          EnumSet<GVRImportSettings> settings = GVRImportSettings.getRecommendedSettingsWith(EnumSet.of(GVRImportSettings.OPTIMIZE_GRAPH, GVRImportSettings.NO_ANIMATION));
          GVRContext ctx = mAvatarRoot.getGVRContext();
          GVRResourceVolume volume = new GVRResourceVolume(ctx, avatarResource);
          GVRSceneObject modelRoot = new GVRSceneObject(ctx);
  
          mAvatarRoot.addChildObject(modelRoot);
          ctx.getAssetLoader().loadModel(volume, modelRoot, settings, false, mLoadModelHandler);
      }
docs: Load the avatar base model
  @param avatarResource    resource with avatar model