Fix Video Unavailable problem at YouTube preview (#26980)

* Fix YouTube preview shows Video Unavailable

* Fix typo on iframe property

* Remove duplicated property

* fix lint error (double-quotes, unknown property)

* renew snapshot for youtube_video.tsx

* fix double quotes and newline error on snapshot for youtube_video.tsx

* fix blank on snapshot for youtube_video.tsx

* Add YouTube Shorts Embed Preview

* Revert "Add YouTube Shorts Embed Preview"

This reverts commit b5fb7a4076ef73774a0e50157f371516b9d383b2.

* Add setting for Youtube Referrer Policy

* fix test code error about Youtube Referrer Policy

* remove mistake changes on `webpack.config.js`

* add test and snapshot about `youtubeReferrerPolicy = true`

* fix errors on ci

* update description of YouTube Referrer Policy

* remove unnecessary whitespace in default_config.ts

* remove ko.json changes to prevent conflict with translate tool

* update snapshot of `youtube_video.test.tsx`

* referrerPolicy on `youtube_video` didn't follow global policy value

https://github.com/mattermost/mattermost/pull/26980#discussion_r1672524152

* update snapshot of `youtube_video.test.tsx`

* Remove obsolete snapshot

* fix typo on index.ts @ youtube_video

---------

Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: Harrison Healey <harrisonmhealey@gmail.com>

webapp/platform/types/src/config.ts

@@ -210,6 +210,7 @@ export type ClientConfig = {
     ServiceEnvironment: string;
     UniqueEmojiReactionLimitPerPost: string;
     UsersStatusAndProfileFetchingPollIntervalMilliseconds: string;
+    YoutubeReferrerPolicy: 'true' | 'false';
 };
 
 export type License = {
@@ -785,6 +786,7 @@ export type ExperimentalSettings = {
     DisableAppBar: boolean;
     DisableRefetchingOnBrowserFocus: boolean;
     DelayChannelAutocomplete: boolean;
+    YoutubeReferrerPolicy: boolean;
 };
 
 export type AnalyticsSettings = {