Change the default for config file download WRT secret seed

Description

We should default to getting the secret seed from the webui when downloading the truenas configuration.

The usefulness of a config file as a backup when it doesn't contain the secret seed is severely compromised (but it can be useful for support and engineering teams to diagnose migration bugs or understand user configuration).

This will be more likely to meet user expectations. I typically download the configuration file to get a backup copy of it. This should reduce instances where users restore an incomplete config and have to redo passwords, app config, etc, etc.

Problem/Justification

Currently our default is to download the config file without the secret seed, which means that the default is not a true configuration backup. This is probably the opposite of what users expect from default option.