[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/routes/route_admin_console.jsx

@@ -173,7 +173,7 @@ export default (
                 component={CustomBrandSettings}
             />
             <Route
-                path='custom_emoji'
+                path='emoji'
                 component={CustomEmojiSettings}
             />
             <Route