Enable merge script failure detection chromium_swarming.expose_merge_script_failures https://crbug.com/1346781#c96 Bug:chromium:1346781 Change-Id: I33c7fcbaa286f4c0401a16c0a03635054c7330f0 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4144179 Reviewed-by: Yuly Novikov <ynovikov@chromium.org> Commit-Queue: Roman Lavrov <romanl@google.com>