Stack Monitoring: Add Enterprise Search monitoring index templates

Author: carlosdelest

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/monitoring/MonitoredSystem.java

@@ -16,6 +16,7 @@ public enum MonitoredSystem {
     KIBANA("kibana"),
     LOGSTASH("logstash"),
     BEATS("beats"),
+    ENTERPRISE_SEARCH("enterprise_search"),
     UNKNOWN("unknown");
 
     private final String system;
@@ -34,6 +35,7 @@ public static MonitoredSystem fromSystem(String system) {
             case "kibana" -> KIBANA;
             case "logstash" -> LOGSTASH;
             case "beats" -> BEATS;
+            case "enterprise_search" -> ENTERPRISE_SEARCH;
             default ->
                 // Return an "unknown" monitored system
                 // that can easily be filtered out if