Make sure test_demo_mode_resources target exists before moving them

BUG=chromium:856442
TEST=None

Change-Id: I54a50d6bdff654b97fccac223c5dffd5484696a2
Reviewed-on: https://chromium-review.googlesource.com/1114683
Commit-Ready: Yilun Lin <yllin@chromium.org>
Tested-by: Pat Erley <perley@chromium.org>
Tested-by: Toni Barzic <tbarzic@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
diff --git a/mod_for_test_scripts/250enableForDemoMode b/mod_for_test_scripts/250enableForDemoMode
index 816d6d4..9c111f1 100755
--- a/mod_for_test_scripts/250enableForDemoMode
+++ b/mod_for_test_scripts/250enableForDemoMode
@@ -5,6 +5,7 @@
 # found in the LICENSE file.
 #
 if [[ -d "${BUILD_DIR}/test_demo_resources" ]]; then
+  mkdir -p "${STATEFUL_DIR}/unencrypted"
   mv "${BUILD_DIR}/test_demo_resources" \
       "${STATEFUL_DIR}/unencrypted/demo_mode_resources"
 fi