Summary

• Added test for waitForStop and StressContainer functionality
• Fixed the timeout test in waitForStop to properly handle container states
• Added test coverage for core container operations including restart, start/stop and remove
• Increased test coverage for the container package from 48% to 49%

Test plan

• All unit tests pass
• Added tests for StressContainer and waitForStop functions
• Added tests for other container interface methods to ensure proper coverage
• Test that timeout handling is working correctly for long-running operations

This PR is part of a larger effort to provide a safety net of tests before refactoring the code to support multiple container runtimes.