Update comment about async flag

helm-charts/images/gcp-filestore-backups/gcp-filestore-backups.py

@@ -155,6 +155,10 @@ def create_backup_if_necessary(
  # return immediately, without waiting for the operation in progress
  # to complete. Given that we only expect to be creating a backup
  # once a day, this feels safe enough to try for now.
+ # The `gcloud filestore backups list` command is instantaneously
+ # populated with new backups, even if they are not done creating.
+ # So we don't have to worry about the async flag not taking those
+ # into account.
  "--async",
  ]
  )