AMBARI-11353. Last item in the drop down menu in metrics selector is not showing up.(xiwang)

ambari-web/app/styles/enhanced_service_dashboard.less

@@ -547,7 +547,6 @@
       margin-top: 2px;
       overflow: auto;
       width: 300px;
-      max-height: 260px;
       border: 1px solid rgba(0, 0, 0, 0.2);
       -webkit-border-radius: 0px;
       -moz-border-radius: 0px;