Fix a race condition with StreamVideo.removeClient()

[aleksandar-apostolov]

Goal

AND-869

Fix a race condition where removeClient would not be finished before calling a new build() causing an exception.

Implementation

Add a synchronized block on the remove same as install.
Ensure that instance is cleared before calling cleanup.
Cleanup is then called on the previous instance regardless of weather a new instance will be created or not.

Testing

Reproduced with a unit test. Covered the scenario with a test.

[github-actions]

PR checklist ✅

All required conditions are satisfied:

• Title length is OK (or ignored by label).
• At least one pr: label exists.
• Sections ### Goal, ### Implementation, and ### Testing are filled.

🎉 Great job! This PR is ready for review.

[github-actions]

SDK Size Comparison 📏

SDK	Before	After	Difference	Status
stream-video-android-core	11.74 MB	11.74 MB	0.00 MB	🟢
stream-video-android-ui-xml	5.68 MB	5.68 MB	0.00 MB	🟢
stream-video-android-ui-compose	6.27 MB	6.27 MB	0.00 MB	🟢

[rahul-lohra]

lgtm

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud