Metal: Temporarily disable asm injection. Some Mac11 bots started to fail after the asm injection started. Disable this path to determine if it was the root cause. Bug: chromium:1522730,chromium:1513738 Change-Id: I2580f124735f576257bb46fbf47394ff845384f8 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5249328 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>