test_image_util.sh: Copy DLC(s) for test images

Preload DLC(s) for test images in stateful in order to allow DLC(s) to
have the capability to be provisioned + used during testing.

BUG=chromium:1025983
TEST=./build_image --board=$B --noenable_rootfs_verification test base
TEST=./mount_gpt_image.sh --board=$B --safe --most_recent -i chromiumos_test_image.bin # + base image
TEST=# Verify placement to /var/cache/dlc-images and missing for base image
TEST=cros_generate_stateful_update_payload -i ../build/images/eve/latest/chromiumos_test_image.bin -o outdir/
TEST=# Verify stateful.tgz includes /var_new/cache/dlc-images
Cq-Depend: chromium:1950718, chromium:1921770
Change-Id: I0eab1f870d6d601b045cd9edb20779098401d598
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/1950815
Tested-by: Jae Hoon Kim <kimjae@chromium.org>
Commit-Queue: Jae Hoon Kim <kimjae@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
2 files changed