add a setting to config.json that allows users to set theme (apache#5584)

Author: Hoang Nguyen

ui/public/config.json

@@ -57,5 +57,6 @@
   "plugins": [],
   "basicZoneEnabled": true,
   "multipleServer": false,
+  "allowSettingTheme": true,
   "docHelpMappings": {}
 }

ui/src/components/page/GlobalLayout.vue

@@ -65,7 +65,7 @@
         </a-drawer>
       </template>
 
-      <template v-if="isDevelopmentMode">
+      <template v-if="isDevelopmentMode || allowSettingTheme">
         <drawer :visible="showSetting" placement="right">
           <div slot="handler">
             <a-button type="primary" size="large">
@@ -146,6 +146,9 @@ export default {
     isDevelopmentMode () {
       return process.env.NODE_ENV === 'development'
     },
+    allowSettingTheme () {
+      return this.$config.allowSettingTheme
+    },
     contentPaddingLeft () {
       if (!this.fixSidebar || this.isMobile()) {
         return '0'