Fix fullscreen eliciting "clear queue" prompt

[Stypox]

What is it?

• Bugfix (user facing)
• Feature (user facing)
• Codebase improvement (dev facing)
• Meta improvement to the project (dev facing)

Description of the changes in your PR

Fixes #12297 by avoiding to pass playAfterConnect=true after toggling fullscreen, which triggered the code to open the player and thus asked to replace the queue.

Fixes #12296 by again avoiding to pass playAfterConnect=true right after switching out of fullscreen, which again triggered the code to open the player and due to "Start main player in fullscreen" being set to true made it so that the VideoDetailFragment went back to fullscreen again.

This PR makes it so that playAfterConnect does not persist, and instead is reset to false after onPlayerConnected is used. Keeping it to true used to not cause issues before #12044, but commit a7a7dc5 added more calls to onPlayerConnected to ensure the video detail fragment remains in sync with the current player. The whole logic around playAfterConnect is very bad, but hopefully this change does not create any problem, since there is no place where playAfterConnect is read other than onPlayerConnected.

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR. You can find more info and a video demonstration on this wiki page.

Due diligence

• I read the contribution guidelines.