Unless the user has a habit of installing APKs from Telegram, the workflow will probably be: tapping the video -> "Telegram cannot play this. Open in an externa

Unless the user has a habit of installing APKs from Telegram, the workflow will probably be: tapping the video -> "Telegram cannot play this. Open in an external app?" -> "APK installation is restricted for this app (click 'settings')" -> "Install unknown apps (click 'allow from this source')" -> Go back -> Open the video again -> "Do you want to install this application?" If you call the app "video player required for this movie" you may be able to convince users to give all of these permissions, but this isn't like the type confusion exploits on Windows where you can go from application to executing a program in one click.