The admin "Default services" setting writes the LDAP serviceEnabled
attribute, but remoteStorage access was also gated behind an unused
per-user Flipper flag that nothing ever enabled, so remoteStorage was
inaccessible for everyone.
Gate remoteStorage on service_enabled? like the other services, and make
the admin toggle reflect the LDAP attribute (this also fixes it reading
current_user instead of the user being viewed). E-Mail keeps its Flipper
gate for now.