Addressing CL comments.

Bug: 260755259
Test: run locally
Change-Id: Ica6e1dbcd0ef5b0db54465d7a33ef13ea53471bc

tools/finalize_sdk.py

@@ -164,6 +164,7 @@ for m in module_names:
             created_dirs[COMPAT_REPO].add(dest_dir.relative_to(COMPAT_REPO))
 
 if args.local_mode:
+    print('Updated prebuilts using locally built artifacts. Don\'t submit or use for anything besides local testing.')
     sys.exit(0)
 
 subprocess.check_output(['repo', 'start', branch_name] + list(created_dirs.keys()))