Update offline demo mode resources location

Updates the location from which offline policy blobs are loaded to match
the new location (set by demo_mode_resources package, rather than
chromeos-assets)

BUG=None

Change-Id: If63e35898c9329d287364ba9f959007824e2db26
Reviewed-on: https://chromium-review.googlesource.com/1173490Reviewed-by: Aga Wronska <agawronska@chromium.org>
Commit-Queue: Toni Baržić <tbarzic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582754}

chrome/browser/chromeos/login/demo_mode/demo_setup_controller.cc

@@ -30,7 +30,7 @@ constexpr char kOfflineDeviceLocalAccountPolicyFileName[] =
 // The policy blob data for offline demo-mode is embedded into the filesystem.
 // TODO(mukai, agawronska): fix this when switching to dm-verity image.
 constexpr const base::FilePath::CharType kOfflineDemoModeDir[] =
-    FILE_PATH_LITERAL("/usr/share/chromeos-assets/demo_mode_resources/policy");
+    FILE_PATH_LITERAL("/usr/share/demo_mode_resources/policy");
 
 bool CheckOfflinePolicyFilesExist(const base::FilePath& policy_dir,
                                   std::string* message) {