WebGL: Disable conformance/misc/uninitialized-test.html on Vulkan

https://crrev.com/c/1767366 breaks this test, but we want to submit it anyway.
We'll fix the breakage afterward. Vulkan is not a shipping configuration yet so
this is OK for now.

Bug: angleproject:3563
Bug: angleproject:3883
Change-Id: If5e26e098228c9f97839d1a492c66353ce8db436
TBR: kbr@chromium.org,syoussefi@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1779540Reviewed-by: James Darpinian <jdarpinian@chromium.org>
Commit-Queue: James Darpinian <jdarpinian@chromium.org>
Cr-Commit-Position: refs/heads/master@{#692339}

content/test/gpu/gpu_tests/test_expectations/webgl_conformance_expectations.txt

@@ -278,7 +278,7 @@ crbug.com/angleproject/2926 [ win nvidia vulkan passthrough ] deqp/data/gles2/sh
 crbug.com/angleproject/2909 [ win nvidia vulkan passthrough ] conformance/ogles/GL/faceforward/faceforward_001_to_006.html [ Failure ]
 crbug.com/angleproject/2722 [ win nvidia vulkan passthrough ] conformance/textures/misc/texture-attachment-formats.html [ Failure ]
 crbug.com/angleproject/2722 [ win nvidia vulkan passthrough ] conformance/renderbuffers/framebuffer-state-restoration.html [ Failure ]
-crbug.com/angleproject/2987 [ win7 nvidia vulkan passthrough ] conformance/misc/uninitialized-test.html [ Failure ]
+crbug.com/angleproject/3883 [ win nvidia vulkan passthrough ] conformance/misc/uninitialized-test.html [ Failure ]
 
 # Vulkan / Win / AMD / Passthrough command decoder
 crbug.com/angleproject/2722 [ win amd vulkan passthrough ] conformance/rendering/clipping-wide-points.html [ Failure ]