Metal: Report Metal being available on iOS simulator Make Metal backend always available on iOS simulator. Currently the GPU family query is not useful as it does not return anything that would enable Metal ANGLE to be used. However, testing on iOS simulator is still useful. Bug: angleproject:7591 Change-Id: I0aa881bb7482fc63bbaa08d5efc10920b3c1af43 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3845154 Auto-Submit: Kimmo Kinnunen <kkinnunen@apple.com> Reviewed-by: Kenneth Russell <kbr@chromium.org> Commit-Queue: Kenneth Russell <kbr@chromium.org>