GH-11201: Add redis_command to sensitive-metadata doc

Specifically to the sensitive-metadata section of the security.adoc

Fixes: #11201

(cherry picked from commit b239c43)

Author: cppwfs

src/reference/antora/modules/ROOT/pages/security.adoc

@@ -184,6 +184,7 @@ The mentioned above validation and filtering might be applied to them before the
 - `spring-integration-redis`
  * `redis_key`
  * `redis_mapKey`
+ * `redis_command`
 
 - `spring-integration-xmpp`
  * `xmpp_to`