Shut down player dialog no longer appears for Chromecast disconnect

[HazardousPeach]

This issue respects the following points:

• This issue is not already reported on GitHub (I've searched it).
• I agree to follow Jellyfin's Code of Conduct.
• This report addresses only a single issue; If you encounter multiple issues, kindly create separate reports for each one.

Describe the bug

When connected to a chromecast, if you hit the "disconnect" button, there used to be a dialog box asking if you wanted to shut down the video, or just disconnect from the player and leave it running, but that dialog box no longer appears. This is because 'EndSession' was removed as a supported message for the chromecast in 588e9e3 (fair enough, the player itself doesn't support that message), but you can end a session on a chromecast, you just call the endSession method of the chromecast sdk instead. But, the code that displays this dialog only checks for a supported EndSession method to decide whether to display the dialog or not, so it misses this is possible and doesn't display the dialog.

Reproduction Steps

1. Clone repo
2. npm install && npm start
3. Open the app (localhost:8080)
4. Connect to a server
5. Cast to a chromecast through the UI cast button
6. Play a video
7. Click the UI cast button and then "disconnect"
8. No dialog box appears

Expected/Actual behaviour

The dialog box should appear asking if I want to shut down the app on the chromecast or just disconnect from it.

Logs

No response

Server version

10.11.6

Web version

a30dd7e

Build version

a30dd7e

Platform

Linux

Browser

Google Chrome Version 144.0.7559.132 (Official Build) (64-bit)

Additional information

No response