Add screen sharing fallback and avatar default in SDK components

[liviu-timar]

🎯 Goal

We need to show a fallback content for the screensharing renderer while the track is loading or is not available. Now we show a track failed to load error.

🛠 Implementation details

• Added a new fallback parameter, starting from ParticipantsLayout and down the tree. ParticipantsLayout is used in CallContent and can be customized in the videoContent parameter.
• The default for the fallback content is the user avatar.

🎨 UI Changes

Before	After

[github-actions]

SDK Size Comparison 📏

SDK	Before	After	Difference	Status
stream-video-android-core	11.21 MB	11.21 MB	0.00 MB	🟢
stream-video-android-ui-xml	5.66 MB	5.66 MB	0.00 MB	🟢
stream-video-android-ui-compose	5.83 MB	5.84 MB	0.02 MB	🟢

[aleksandar-apostolov]

Why is this still a draft?

[Copilot]

Copilot reviewed 5 out of 6 changed files in this pull request and generated no comments.

Files not reviewed (1)

• stream-video-android-ui-compose/api/stream-video-android-ui-compose.api: Language not supported

Comments suppressed due to low confidence (1)

stream-video-android-ui-compose/src/main/kotlin/io/getstream/video/android/compose/ui/components/call/renderer/internal/ScreenShareVideoRenderer.kt:59

• [nitpick] Consider using a consistent naming convention for the fallback content parameter across all screen sharing renderers. In some files it is named 'fallbackContent' while in others it is 'screenSharingFallbackContent'.

fallbackContent: @Composable (ScreenSharingSession) -> Unit = {

[sonarqubecloud]

Quality Gate failed

Failed conditions
37.5% Coverage on New Code (required ≥ 80%)
28.8% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud