Kubernetes bug fixes & small improvements

[jfzunigac]

Summary

• Fix comparator contract violation in log stream sorting: Replaced CompositeFileComparator with a snapshot-based comparator that captures file modification timestamps before sorting. This prevents IllegalArgumentException: Comparison method violates its general contract! when files are modified during sorting (e.g., by log rotation), which was causing some the initial pod discovery thread to crash in production.
• Add directory check before registering recursive watch: Check if path is a directory in RecursiveFSEventProcessor before calling registerPath() to avoid unnecessary error logging for file paths.
• Fix flaky TestPodAllowlist test: Stop the shared HTTP server in @afterclass and stop KubeService in @after to prevent thread leaks and "VM terminated without saying goodbye" errors.
• Inject pod name tag to metrics if available