Fix channel list blinking UI when resuming from a paused state

[andremion]

🎯 Goal

Fix the blinking UI when resuming from a paused state, for example, after switching back from the recent apps.

🛠 Implementation details

The previous implementation switched the channel list by the loading UI even when there were results in the list, causing the blink when the screen is resumed from a paused state.

The proposed implementation prevents that blinking by not rendering the loading UI if there is any result.

🎨 UI Changes

Before	After

🧪 Testing

It can be reproduced by switching apps from the recent apps or resuming from a minimized state.

☑️Contributor Checklist

General

• I have signed the Stream CLA (required)
• Assigned a person / code owner group (required)
• Thread with the PR link started in a respective Slack channel (#android-chat-core or #android-chat-ui) (required)
• 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

🎉 GIF