fix: attachments menu blends with background [WPB-15102]

[saleniuk]

WPB-15102 [Android] File sharing overlay matches background color of conversation in dark mode

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PR Submission Checklist for internal contributors

• The PR Title

  • conforms to the style of semantic commits messages¹ supported in Wire's Github Workflow²
  • contains a reference JIRA issue number like SQPIT-764
  • answers the question: If merged, this PR will: ... ³

• The PR Description

  • is free of optional paragraphs and you have filled the relevant parts to the best of your ability

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What's new in this PR?

Issues

Attachments menu matches the background color of the conversation screen, making it difficult to distinguish the overlay from the background.

Solutions

Rearrange some surface colors, add border to the attachments menu in the way so that it is drawn properly even during animations.

Testing

How to Test

Open attachments menu on light and dark mode.

Attachments (Optional)

Before	After

animation_10x_slower.mp4

[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-commenter]

Codecov Report

Attention: Patch coverage is 0% with 14 lines in your changes missing coverage. Please review.

Project coverage is 45.69%. Comparing base (8792a6c) to head (3a06393).
Report is 1 commits behind head on release/candidate.

Files with missing lines	Patch %	Lines
.../ui/home/messagecomposer/EnabledMessageComposer.kt	0.00%	14 Missing ⚠️

Additional details and impacted files

@@                  Coverage Diff                  @@
##           release/candidate    #3761      +/-   ##
=====================================================
- Coverage              45.73%   45.69%   -0.04%     
=====================================================
  Files                    473      473              
  Lines                  16094    16108      +14     
  Branches                2717     2718       +1     
=====================================================
  Hits                    7361     7361              
- Misses                  7972     7986      +14     
  Partials                 761      761              

Files with missing lines	Coverage Δ
...alling/ongoing/participantsview/ParticipantTile.kt	0.00% <ø> (ø)
.../ui/home/messagecomposer/EnabledMessageComposer.kt	0.00% <0.00%> (ø)

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Built wire-android-staging-compat-pr-3761.apk is available for download