Do not try to upload if the list of artifacts is empty.

Bug: https://github.com/flutter/flutter/issues/81855
Change-Id: I76680d9a355f0acb9771171d47b9114ea00519f7
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/31280
Reviewed-by: Drew Roen <drewroen@google.com>
Commit-Queue: Godofredo Contreras <godofredoc@google.com>
diff --git a/recipes/engine_v2/builder.py b/recipes/engine_v2/builder.py
index 9dad0b6..ac9ad4e 100644
--- a/recipes/engine_v2/builder.py
+++ b/recipes/engine_v2/builder.py
@@ -130,7 +130,7 @@
       base_name = api.path.basename(full_include_path)
       api.file.ensure_directory('Ensuring %s' % archive_dir.join(rel_path), archive_dir.join(rel_path))
       api.file.copy('Copy %s' % include_path, full_include_path, archive_dir.join(rel_path, base_name))
-  if archive_config.get('type') == 'gcs':
+  if archive_config.get('type') == 'gcs' and archive_config.get('include_paths', []):
     commit = api.repo_util.get_commit(checkout.join('flutter'))
     api.gsutil.upload(
         source='%s/*' % archive_dir, bucket='flutter_archives_v2',