Prevent user from starting LLS in thread

[bmarty]

Content

Prevent user from starting LLS in thread. We only allow sharing the current location in a thread.

Motivation and context

Part of #6764.

Other points of #6764 has to be handled by the SDK, this is done in matrix-org/matrix-rust-sdk#6563

Screenshots / GIFs

Tests

• enable LLS flag
• open a room
• try to share location
• see that you can start a LLS
• open a thread
• try to share location
• see that you cannot start a LLS

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• This PR was made with the help of AI:
  • Yes. In this case, please request a review by Copilot.
  • No.
• 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 defines 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

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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

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.15%. Comparing base (e49e183) to head (7f54507).
⚠️ Report is 4 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #6767   +/-   ##
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  Coverage    81.15%   81.15%           
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  Files         2647     2647           
  Lines        74042    74045    +3     
  Branches      9579     9581    +2     
========================================
+ Hits         60091    60094    +3     
  Misses       10417    10417           
  Partials      3534     3534           

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[jmartinesp]

Thanks!

[jmartinesp]

Should this also exclude pinned events timeline? The current UI won't allow you to start a live location share in that screen, but it may be worth it to explicitly ensure that here.

[bmarty]

I thought about having all the case in the when statement, but I preferred to keep the code simple. Since there is no composer in Pinned event timeline, I guess it's fine. Maybe Timeline.Mode could have a read-only / writable concept.