Draft: Remove white background from stickers/images

[jmartinesp]

Content

Motivation and context

Screenshots / GIFs

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 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

[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

❌ Patch coverage is 53.84615% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.29%. Comparing base (c8500fd) to head (3e7d169).
⚠️ Report is 157 commits behind head on develop.

Files with missing lines	Patch %	Lines
...ges/impl/timeline/components/MessageEventBubble.kt	25.00%	2 Missing and 1 partial ⚠️
.../components/blurhash/BlurHashBackgroundModifier.kt	40.00%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #6068      +/-   ##
===========================================
- Coverage    81.30%   81.29%   -0.01%     
===========================================
  Files         2558     2558              
  Lines        68793    68797       +4     
  Branches      8827     8827              
===========================================
- Hits         55933    55931       -2     
- Misses        9586     9590       +4     
- Partials      3274     3276       +2     

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