feat: feature flag for invite functionalities

react/features/base/flags/constants.js

  */
 export const CHAT_ENABLED = 'chat.enabled';
 
+/**
+ * Flag indicating if invite functionality should be enabled.
+ * Default: enabled (true).
+ */
+export const INVITE_ENABLED = 'invite.enabled';
+
 /**
  * Flag indicating if recording should be enabled in iOS.
  * Default: disabled (false).

react/features/invite/components/add-people-dialog/native/InviteButton.js

 
 import type { Dispatch } from 'redux';
 
+import { getFeatureFlag, INVITE_ENABLED } from '../../../../base/flags';
 import { translate } from '../../../../base/i18n';
 import { IconAddPeople } from '../../../../base/icons';
 import { connect } from '../../../../base/redux';
  * @returns {Object}
  */
 function _mapStateToProps(state: Object, ownProps: Object) {
-    const addPeopleEnabled = isAddPeopleEnabled(state) || isDialOutEnabled(state);
+    const addPeopleEnabled = getFeatureFlag(state, INVITE_ENABLED, true)
+        && (isAddPeopleEnabled(state) || isDialOutEnabled(state));
     const { visible = Boolean(addPeopleEnabled) } = ownProps;
 
     return {