DOCSP-42940 -- Add rolling restart note-v6.0-backport (342) (#551)

# Backport

This will backport the following commits from `master` to `v6.0`:
- [DOCSP-42940 -- Add rolling restart note
(#342)](10gen/docs-ops-manager#342)

<!--- Backport version: 9.6.1 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sorenlouv/backport)

Author: jvincent-mongodb

source/includes/steps-source-enable-authentication.yaml

@@ -125,6 +125,9 @@ content: |
      retrieve all groups which that LDAP user possesses and transforms those
      groups into their equivalent MongoDB roles.
 
+     MongoDB processes restart in a rolling fashion when you apply 
+     these changes.
+
   Skip this step if you selected :guilabel:`Saslauthd` in the previous
   step.