Even if a SaaS Plan has every feature enabled in the SaaS Configurator (including Memberships), when a sub-account subscribes to that plan, the Certificates Feature for that sub-account is always disabled.

This means we have to manually turn it on for every sub-account, which kinda defeats the purpose of the SaaS Configurator.

Please fix this oversight to make sure it's enabled automatically for sub-accounts where the appropriate SaaS Configurator features are enabled.