feat(MediaSettings) - Adjust the preview background update to only change in video when confirmed

[DorraJaouad]

☑️ Resolves

• Fix Preview video backgrounds when in a call #9379

🚧 Tasks

• Code review
• Visual review

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not required
• 📘 API documentation in docs/ has been updated or is not required
• 📗 User documentation in https://github.com/nextcloud/documentation/tree/master/user_manual/talk has been updated or is not required
• 🔖 Capability is added or not needed

[Antreesy]

Seems to work, nothing blocking - just remarks about wording / naming

[marcoambrosini]

Hi @DorraJaouad & @Antreesy :)
I think "Apply settings" works well for every setting there, and we should use it it in the devices page too. By that I mean that both camera and microphone device settings shouldn't immediately affect the streams in the call but only the preview videos and mic level.
Changes should occur only when "apply settings" button is clicked.
What do you think?

[Antreesy]

Changes should occur only when "apply settings" button is clicked. What do you think?

Should be possible to split this logic to preview and apllied device, same as for background, so I'd like to see it
UPD: or maybe it requires some modifications to be done at MediaDevicesManager, so I'd like to not mess with the working code at this point...

[Antreesy]

🎉

[Antreesy]

/backport to stable27