[56] Improve snapshot tests

[bychkovdmitry]

🎯 Goal

https://github.com/GetStream/android-internal-board/issues/56

Improve snapshot tests

🛠 Implementation details

Noticed several areas of improvement:

• Fixed channel item for muted channel
• Improved snapshots in dark mode
• Fixed channel name formatter

🧪 Testing

Execute ./scripts/uitests/record_snapshots.sh and ensure that XML avatars no longer have black background.

After the PR is merged, the screenshots need to be updated with the following action: https://github.com/GetStream/stream-chat-android/actions/workflows/snapshot-record.yaml

☑️Contributor Checklist

General

• [x] I have signed the Stream CLA (required)
• [x] Assigned a person / code owner group (required)
• [x] Thread with the PR link started in a respective Slack channel (#android-chat-core or #android-chat-ui) (required)
• [x] PR targets the develop branch
• [x] PR is linked to the GitHub issue it resolves

Code & documentation

• [ ] Changelog is updated with client-facing changes
• [ ] New code is covered by unit tests
• [ ] Comparison screenshots added for visual changes
• [ ] Affected documentation updated (KDocs, docusaurus, tutorial)

☑️Reviewer Checklist

• [ ] UI Components sample runs & works
• [ ] Compose sample runs & works
• [ ] UI Changes correct (before & after images)
• [ ] Bugs validated (bugfixes)
• [ ] New feature tested and works
• [ ] Release notes and docs clearly describe changes
• [ ] All code we touched has new or updated KDocs