project-lakitu: Set file permissions of /boot/efi/boot/grub.cfg to 400

BUG=b/177854826
TEST=presubmit
RELEASE_NOTE=None

Change-Id: I0cd6683684602abbbf2174e12181a6051fbb8dd4
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/11774
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Reviewed-by: Roy Yang <royyang@google.com>
1 file changed