Skip Texture2DArrayCopy.UnsignedByteFormats on D3D11. This test appears to be flaky. Bug: angleproject:2896 Change-Id: Ib0c0ac9ab170edf0f31506f847307bee9b78f770 Reviewed-on: https://chromium-review.googlesource.com/c/1286913 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>