rn,flags: add flag to show/hide video share button

react/features/base/flags/constants.js

  */
 export const TOOLBOX_ALWAYS_VISIBLE = 'toolbox.alwaysVisible';
 
+/**
+ * Flag indicating if the video share button should be enabled
+ * Default: enabled (true).
+ */
+export const VIDEO_SHARE_BUTTON_ENABLED = 'video-share.enabled';
+
 /**
  * Flag indicating if the welcome page should be enabled.
  * Default: disabled (false).

react/features/youtube-player/components/VideoShareButton.js

 
 import type { Dispatch } from 'redux';
 
+import { getFeatureFlag, VIDEO_SHARE_BUTTON_ENABLED } from '../../base/flags';
 import { translate } from '../../base/i18n';
 import { IconShareVideo } from '../../base/icons';
 import { getLocalParticipant } from '../../base/participants';
  * Maps part of the Redux state to the props of this component.
  *
  * @param {Object} state - The Redux state.
+ * @param {Object} ownProps - The properties explicitly passed to the component instance.
  * @private
  * @returns {Props}
  */
-function _mapStateToProps(state): Object {
+function _mapStateToProps(state, ownProps): Object {
     const { ownerId, status: sharedVideoStatus } = state['features/youtube-player'];
     const localParticipantId = getLocalParticipant(state).id;
+    const enabled = getFeatureFlag(state, VIDEO_SHARE_BUTTON_ENABLED, true);
+    const { visible = enabled } = ownProps;
 
     if (ownerId !== localParticipantId) {
         return {
             _isDisabled: isSharingStatus(sharedVideoStatus),
-            _sharingVideo: false };
+            _sharingVideo: false,
+            visible };
     }
 
     return {
-        _sharingVideo: isSharingStatus(sharedVideoStatus)
+        _sharingVideo: isSharingStatus(sharedVideoStatus),
+        visible
     };
 }