Fix Wireframe not rendering when using Vulkan API.

Jira ticket: https://jira.unity3d.com/browse/UUM-36914

Initial context + initial fix + explanation: https://github.cds.internal.unity3d.com/unity/unity/pull/25910
More context for the Vulkan Terrain edge case: https://ono.unity3d.com/unity/unity/pull-request/111240/_/graphics/vulkan/case-1205332

Following this PR, the problem is also in latest Trunk for the non-RG path. We have to fix it too, which is the goal of this PR. I simply used the same strategy than the other PR.

Author: YohannVaastUnity

Packages/com.unity.render-pipelines.universal/Runtime/RenderingUtils.cs

@@ -252,7 +252,19 @@ internal static void FinalBlit(
                 cmd.SetRenderTarget(BuiltinRenderTextureType.CameraTarget,
                     loadAction, storeAction, // color
                     RenderBufferLoadAction.DontCare, RenderBufferStoreAction.DontCare); // depth
-                cmd.Blit(source.nameID, destination.nameID);
+
+                // Necessary to disable the wireframe here, since Vulkan is handling the wireframe differently
+                // to handle the Terrain "Draw Instanced" scenario (Ono: case-1205332).
+                if (SystemInfo.graphicsDeviceType == GraphicsDeviceType.Vulkan)
+                {
+                    cmd.SetWireframe(false);
+                    cmd.Blit(source, destination);
+                    cmd.SetWireframe(true);
+                }
+                else
+                {
+                    cmd.Blit(source, destination);
+                }
             }
             else if (source.rt == null)
                 Blitter.BlitTexture(cmd, source.nameID, scaleBias, material, passIndex);  // Obsolete usage of RTHandle aliasing a RenderTargetIdentifier