message: Fix colorGradingAsSubpass when dithering is off.
  This fixes the blank screen seen with Vulkan when all view options are
  disabled.
diff: @@ -119,8 +119,8 @@ fragment {
  #else
  postProcess.color = dithered;
  #endif
  - postProcess.tonemappedOutput = postProcess.color;
  }
  + postProcess.tonemappedOutput = postProcess.color;
  }
  }
  