update hooks: slip in public stout overlay

For people who have peppy builds already, regen their board configs
so that they also include the public overlay.

BUG=chrome-os-partner:22327
TEST=`./update_chroot` converts a private-only /build/peppy to include
the public repo

CQ-DEPEND=If6f4da10db7388822a2dab2b4f17d93446f8d36f

Change-Id: I4e8061b6813bdb7cc3ac47de82183466dc3e63f5
Reviewed-on: https://chromium-review.googlesource.com/174090
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Shawn Nematbakhsh <shawnn@chromium.org>
Tested-by: Shawn Nematbakhsh <shawnn@chromium.org>
1 file changed