Fixed a bug where the dash character (-) was incorrectly included as a flag when parsing command arguments. Now only the actual flag characters after the dash are added to the flags set.

Added unit tests to verify the correct parsing behavior.

…erLauncher

- Added stdout consumption to prevent buffer overflow
- Implemented process timeout (30 seconds) with forceful termination
- Added exit value validation and logging
- Ensured process cleanup in finally block
- Maintained backward compatibility

This prevents process hangs and ensures proper resource cleanup.

…agement

[ZEPPELIN-6258] Improve Process resource management in SparkInterpreterLauncher

…eAsStream