scripts: Skip DLC installations for factory shim images

Stateful partition is much more compact on factory shim layouts.
Also, it is unnecessary to keep factory process working with factory
installed DLCs.

BUG=b:208867476
TEST=CQ

Change-Id: Ic8eb66b43f3d10f366d820bae4a6ae7681a3a7e8
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/3400743
Tested-by: Jae Hoon Kim <kimjae@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Jae Hoon Kim <kimjae@chromium.org>
Reviewed-by: Lizzy Presland <zland@google.com>
diff --git a/build_library/base_image_util.sh b/build_library/base_image_util.sh
index 02f2d30..d152d70 100755
--- a/build_library/base_image_util.sh
+++ b/build_library/base_image_util.sh
@@ -517,8 +517,12 @@
 
   # Generate DLCs and copy their metadata to the rootfs + factory install DLC
   # images into stateful partition.
-  build_dlc --sysroot="${BOARD_ROOT}" --rootfs="${root_fs_dir}" \
-    --stateful="${stateful_fs_dir}" --board="${BOARD}" --factory-install
+  if should_build_image ${CHROMEOS_FACTORY_INSTALL_SHIM_NAME}; then
+    info "Skipping DLC copying for factory shim images."
+  else
+    build_dlc --sysroot="${BOARD_ROOT}" --rootfs="${root_fs_dir}" \
+      --stateful="${stateful_fs_dir}" --board="${BOARD}" --factory-install
+  fi
 
   restore_fs_contexts "${BOARD_ROOT}" "${root_fs_dir}" "${stateful_fs_dir}"