AMBARI-12891. Config group select tweaks.(xiwang)

ambari-web/app/styles/application.less

@@ -5439,6 +5439,11 @@ input[type="radio"].align-checkbox, input[type="checkbox"].align-checkbox {
   .select-create-config-group-div {
     margin-left: 20px;
     margin-bottom: 20px;
+    .btn-group >.dropdown-menu {
+      max-height: 160px;
+      max-width: 300px;
+      overflow: scroll;
+    }
   }
   .message{
     color: #777;

ambari-web/app/views/common/configs/service_config_view.js

@@ -313,8 +313,8 @@ App.ConfigGroupDropdownView = Ember.TextField.extend({
    */
   disabled: function () {
     if (this.get('controller.isInstaller')) return false;
-    return !this.get('controller.versionLoaded');
-  }.property('controller.versionLoaded', 'controller.isInstaller'),
+    return !this.get('controller.versionLoaded') || this.get('controller.isHostsConfigsPage');
+  }.property('controller.versionLoaded', 'controller.isInstaller', 'controller.isHostsConfigsPage'),
 
   didInsertElement: function() {
     var self = this;