[stable_version] Add support for milestone info and firmware image locations.

Automated repair needs to be able to download arbitrary firmware images that
are not necessarily bundled with the OS. In order to do this, we store a
fragment of the path to the Google Storage location, in the same format as
the FAFT stable version.

BUG=b/179386397
TEST=regenerate configs.

Change-Id: I75f61c26a9a8bed566a7b83e9b27fc660003cd3c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2676168
Commit-Queue: Gregory Nisbet <gregorynisbet@google.com>
Reviewed-by: Allen Li <ayatane@chromium.org>
Reviewed-by: Otabek Kasimov <otabek@google.com>
2 files changed