DOCSP-44556-add-step-restart-v8.0-backport (489) (#497)

# Backport

This will backport the following commits from `master` to `v8.0`:
- [DOCSP-44556-add-step-restart
(#489)](https://github.com/10gen/docs-ops-manager/pull/489)

<!--- Backport version: 9.5.1 -->

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

Author: gmiller-mdb

source/includes/steps-add-ca-cert-to-om-truststore.yaml

@@ -24,9 +24,24 @@ content: |
   .. code-block:: sh
 
     sudo /opt/mongodb/mms/jdk/bin/keytool -noprompt -storepass changeit -list -v -keystore /opt/mongodb/mms/jdk/lib/security/cacerts | grep -i Webhook_CA
+
 ---
 stepnum: 3
 level: 4
+ref: restart-ops-manager
+title: "Restart Ops Manager."
+content: |
+
+  Restart the |onprem| server in order for the certificates to reload and the
+  change to take effect. 
+
+  .. code-block:: sh
+
+    sudo systemctl restart mongodb-mms
+
+---
+stepnum: 4
+level: 4
 ref: add-credentials-automation-click-credentials
 title: "Test an HTTPS request to Ops Manager to confirm connectivity."
 content: |