Add temporary feature flag to control padlocks

This default on feature flag will help in case we want to trial padlocks on vs.
off this weekend.

Fixes https://github.com/vector-im/riot-web/issues/12166

src/components/views/rooms/InviteOnlyIcon.js

@@ -17,6 +17,7 @@ limitations under the License.
 import React from 'react';
 import { _t } from '../../../languageHandler';
 import * as sdk from '../../../index';
+import SettingsStore from '../../../settings/SettingsStore';
 
 export default class InviteOnlyIcon extends React.Component {
     constructor() {
@@ -36,6 +37,10 @@ export default class InviteOnlyIcon extends React.Component {
     };
 
     render() {
+        if (!SettingsStore.isFeatureEnabled("feature_invite_only_padlocks")) {
+            return null;
+        }
+
         const Tooltip = sdk.getComponent("elements.Tooltip");
         let tooltip;
         if (this.state.hover) {