firmware: add chroot to Request messages.

The Build API handles entering the chroot, and needs to know where it
is.

BUG=b:172268309
TEST=generate

Change-Id: I2490b0d6507fb73f0f97e714d75beedc6c2e9cb6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2525869
Auto-Submit: LaMont Jones <lamontjones@chromium.org>
Commit-Queue: Jett Rink <jettrink@chromium.org>
Commit-Queue: Sean McAllister <smcallis@google.com>
Reviewed-by: Jett Rink <jettrink@chromium.org>
Reviewed-by: Sean McAllister <smcallis@google.com>
2 files changed