[PLT-6969] System console setting for the emoji picker (#6809)

* system console setting for the emoji picker

* remove state.emojiPickerEnable

* update url to /admin_console/customization/emoji

webapp/components/admin_console/admin_sidebar.jsx

@@ -551,11 +551,11 @@ export default class AdminSidebar extends React.Component {
                             >
                                 {customBranding}
                                 <AdminSidebarSection
-                                    name='custom_emoji'
+                                    name='emoji'
                                     title={
                                         <FormattedMessage
-                                            id='admin.sidebar.customEmoji'
-                                            defaultMessage='Custom Emoji'
+                                            id='admin.sidebar.emoji'
+                                            defaultMessage='Emoji'
                                         />
 
                                     }