Bug Vignetting not visible in player/builds

Hi, looks like vignette is missing in final builds, when targeting Vulkan. Anyone having similar issues? Other effects like bloom works without issues. Also vignette working just fine with OpenGL.

How to reproduce

1. Create new project
2. Add Post Processing through the Package Manager
3. Add Post Processing layer on the camera - set the layer to Post Processing
4. Add Post Processing to an empty GameObject - set the layer to Post Processing
5. Enable some vignette settings - make sure changes are visible in the Game-view.
6. Go to File -> Build Settings ... -> Player Settings ... -> Un-check "Auto Graphics API for Linux", move Vulkan to the top.
7. Linux x86_64 as target platform - then Build And Run.

Tested with

• Unity 2018.3.0f2 and 2018.2.16f1
• Post Processing 2.1.2
• Vulkan 1.1.82
• Nvidia 410.78 (proprietary)