feat(design) : update send button background

[ganfra]

Content

Update the send button background colors.

Motivation and context

https://www.figma.com/design/Ni6Ii8YKtmXCKYNE90cC67/Timeline-(new)?node-id=2274-39944&m=dev

Screenshots / GIFs

See recorded screenshots.

Tests

• Step 1
• Step 2
• Step ...

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• Changes have been tested on an Android device or Android emulator with API 23
• 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
• Pull request includes a sign off
• You've made a self review of your PR

[github-actions]

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83.09%. Comparing base (f3ee89d) to head (2cddb32).
Report is 7 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #4000      +/-   ##
===========================================
- Coverage    83.09%   83.09%   -0.01%     
===========================================
  Files         1808     1808              
  Lines        45887    45878       -9     
  Branches      5395     5395              
===========================================
- Hits         38131    38122       -9     
  Misses        5862     5862              
  Partials      1894     1894              

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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

[bmarty]

Thanks for handling this.