Fix broken Element Call in 25.05.0

[bmarty]

Content

Ensure that the Rust room is not closed while the driver needs it.
I tried to make a wider rework by just using a Room (from Rust), but it does not work since we need an active timeline.

Motivation and context

Fix regression introduced in #4678 and so closes #4689

Screenshots / GIFs

Tests

• Start a call
• The call starts

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• Changes have been tested on an Android device or Android emulator with API 24
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request title will be used in the release note, it clearly define what will change for the user
• Pull request includes screenshots or videos if containing UI changes
• You've made a self review of your PR

[bmarty]

We cannot destroy the room here since it will close the FFI Room and the WidgetDriver needs it to work properly.

[jmartinesp]

Thanks, and sorry for the regression 😞 .

[github-actions]

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.

Project coverage is 80.11%. Comparing base (5fb0fc0) to head (6587632).
Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
...d/libraries/matrix/impl/widget/RustWidgetDriver.kt	0.00%	2 Missing ⚠️
...droid/libraries/matrix/impl/room/JoinedRustRoom.kt	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #4694      +/-   ##
===========================================
- Coverage    80.11%   80.11%   -0.01%     
===========================================
  Files         2127     2127              
  Lines        56292    56294       +2     
  Branches      7018     7018              
===========================================
- Hits         45101    45100       -1     
- Misses        8779     8782       +3     
  Partials      2412     2412              

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[jmartinesp]

Thanks, and sorry for the regression 😞 .