Lower 7 day SAML SSO Session Expiry to 1 day

We've greatly improved the experience when a SAML SSO session expires. In order to make our experience even more secure, I'd like to lower the default expiry from 7 days to 1 day.

Change the constant at https://gitlab.com/gitlab-org/gitlab/-/blob/4ec07eb4cf0ec25f38a40157f513747d70c0fab0/ee/lib/gitlab/auth/group_saml/sso_enforcer.rb#L7
Fix/write any necessary tests.

Also, inform Application ~Support team when merged.

Edited Jan 20, 2021 by Drew Blessing