give chronos lpadmin access

Printer admin tasks will come from the chronos user, I believe.

BUG=chrome-os-partner:47758,chrome-os-partner:49267
TEST=`emerge-${BOARD} cups`, start cups, try running 'lpadmin' tasks
     as chronos user

Change-Id: I7a5752b659dc03c209a7e5dba371fcdc41013386
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/328021
Reviewed-by: Benson Leung <bleung@chromium.org>
diff --git a/profiles/base/accounts/group/lpadmin b/profiles/base/accounts/group/lpadmin
index a4f1e80..3109afc 100644
--- a/profiles/base/accounts/group/lpadmin
+++ b/profiles/base/accounts/group/lpadmin
@@ -1,3 +1,3 @@
 group:lpadmin
 gid:269
-users:cups
+users:chronos,cups