code: public void onSplashScreenCreated(GVRSceneObject splashScreen) {
          GVRTransform transform = splashScreen.getTransform();
          transform.setPosition(0, 0, DEFAULT_SPLASH_Z);
      }
docs: Override this method to change the default splash screen size or
  position.
  
  This method will be called <em>before</em> {@link #onInit(GVRContext)
  onInit()} and before the normal render pipeline starts up. In particular,
  this means that any {@linkplain GVRAnimation animations} will not start
  until the first {@link #onStep()} and normal rendering starts.
  
  @param splashScreen
  The splash object created from
  {@link #getSplashTexture(GVRContext)},
  {@link #getSplashMesh(GVRContext)}, and
  {@link #getSplashShader(GVRContext)}.
  
  @since 1.6.4