ceph: clarify docs around settings configmap

The configmap for advanced configuration can be created before the
cluster is created. In that case, the daemons will all pick up the
settings the first time they are started. Otherwise, the daemons
need to be restarted
Signed-off-by: travisn <tnielsen@redhat.com>

Documentation/ceph-advanced-configuration.md

@@ -436,7 +436,9 @@ MDS, and RGW daemons as an `/etc/ceph/ceph.conf` file.
 **WARNING:** Rook performs no validation on the config, so the  validity of the settings is the
 user's responsibility.
 
-Each daemon will need to be restarted where you want the settings applied:
+If the `rook-config-override` ConfigMap is created before the cluster is started, the Ceph daemons
+will automatically pick up the settings. If you add the settings to the ConfigMap after the cluster
+has been initialized, each daemon will need to be restarted where you want the settings applied:
 
 - mons: ensure all three mons are online and healthy before restarting each mon pod, one at a time.
 - mgrs: the pods are stateless and can be restarted as needed, but note that this will disrupt the