brillo image: Different summary message for brillo tools.

Currently, both brillo image and cros image display the same summary message.
This CL changes it so brillo image displays a different summary message. It is
done by passing '--toolset=brillo' to build_image.

TEST=unittests + manual tests
CQ-DEPEND=CL:275748, CL:275702, CL:275726

Change-Id: I62b75c6018177f53f96c647bd3dc07a968ae5c38
Reviewed-by: Steve Fung <>
Commit-Queue: Ralph Nathan <>
Trybot-Ready: Ralph Nathan <>
Tested-by: Ralph Nathan <>
2 files changed