bisect-kit: android_util: fix typo

BUG=b:169377050
TEST=manually

Change-Id: I76f9ea49458c9ca086c310aa521a09c7fee1d38d
diff --git a/bisect_kit/android_util.py b/bisect_kit/android_util.py
index 948d7cb..e1e972b 100644
--- a/bisect_kit/android_util.py
+++ b/bisect_kit/android_util.py
@@ -163,7 +163,7 @@
   """
   if os.environ.get('SKYLAB_CLOUD_SERVICE_ACCOUNT_JSON'):
     api = AndroidInternalApi()
-    api.download_artifact(build_id, flvor, filename,
+    api.download_artifact(build_id, flavor, filename,
                           os.path.join(dest_folder, filename))
   else:
     fetch_artifact_from_g3(flavor, build_id, filename, dest_folder)