build_image: insert container devkey into image

This way we can verify the container verification stack.

BUG=chromium:660209
TEST=build_image included the new container pub key

Change-Id: I1cf2dfe3386b6bc5bdae72f651df982e5f419667
Reviewed-on: https://chromium-review.googlesource.com/430830
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
1 file changed