In order to convert the flutter/packages FTL tests from Cirrus to LUCI, we need LUCI access to the secrets used by those tests. It looks like the FTL key is already there, but we need the Google Maps API key as well

See b/267472828 for more details about the secrets from the last time we moved them. @yusuf-goog Could you handle this? I tried to follow the instructions you pointed me to, but got a permission error on the encryption step, so it appears I don't have the necessary privileges. If the referenced maps API key could be uploaded as google_maps_api_key.encrypted that would be great.