Update WebGL2 Metal expectations.

Re-suppress deqp/functional/gles3/uniformbuffers/random.html

Bug: angleproject:6430
Bug: chromium:1286044
Change-Id: I2d2cad13f10a9bcaeec786b7599298e3c4f40768
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3381266


Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Alexis Hétu <sugoi@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
Cr-Commit-Position: refs/heads/main@{#958142}