Fix Volumetric Fog rasterization on Vulkan

Content/Shaders/VolumetricFog.flax

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:872ac3560279bfd0aeb989ebac1b49750dd142b985bc40058888dfd2b63fe9b2
-size 13214
+oid sha256:e5e4afe341dbadc3fcfe18e582b9ab476e61c50a248ed71e0a37c22146e1ea3a
+size 13272

Source/Shaders/VolumetricFog.shader

@@ -125,6 +125,9 @@ Quad_VS2GS VS_WriteToSlice(float2 TexCoord : TEXCOORD0, uint LayerIndex : SV_Ins
 		float radius = sqrt(ViewSpaceBoundingSphere.w * ViewSpaceBoundingSphere.w - depthOffset * depthOffset);
 		float3 positionVS = float3(ViewSpaceBoundingSphere.xy + (TexCoord * 2 - 1) * radius, depth);
 		output.Vertex.Position = mul(float4(positionVS, 1), ViewToVolumeClip);
+#if VULKAN
+        output.Vertex.Position.y *= -1;
+#endif
 	}
 	else
 	{