Note: ** according to comments from dev, we should edit edit the doc sample to not use frame bufferfetch as the blur effect samples pixel from another location, not current pixel.

*Steps to reproduce:*

1. Open attached project (RG_FBFetch.zip)

2. PlayerSettings > Graphics API > make sure Vulkan is on top of the list

3. Open SampleScene

*Actual results:* Only vertical blur works.

*Expected results:* Both vertical and horizontal blur works

*Reproducible with versions:* 6000.0.6f1.6450.492

*Not reproducible with versions:* 

*Can’t test with versions:* 

*Tested on (OS):*
Windows Vulkan editor
Windows DX11 editor (rendering fine)
Windows DX12 editor (rendering fine)

*Notes:*
* The blur sample comes from doc [https://docs.unity3d.com/Packages/com.unity.render-pipelines.universal@17.0/manual/renderer-features/create-custom-renderer-feature.html]