Set the session exchange config.

The REST interface to set the configuration for session exchange. This is the list of allowed redirect_url that can be used in the TokenExchange API for a tenant.
{ "allowedURLs": [ "https://url_regex_1", "https://url_reg_ex2" ] }
'allowedURLs' The entries in the list are treated as regular expressions.
When calling the TokenExchange API, the redirect_url parameter must match one of these conditions:
- URL paths that start with the tenant domain are allowed by default, "".
- Relative paths, that start with "/", are allowed by default.
- Else, it must match one of the regular expressions in this list.