[BUG] Systemd services aren't created after installation for DEBIAN machines with python3

[Shantanu Mishra]

setup.py script tries to create systemd service after copying packages for DEBIAN, for which it has a check at line 220

if debian_has_systemd():
            set_systemd_files(data_files, dest=systemd_dir_path)

def debian_has_systemd():
    try:
        return subprocess.check_output(
            ['cat', '/proc/1/comm']).strip() == 'systemd'
    except subprocess.CalledProcessError:
        return False

The function return type is different for python3 and python (b'systemd' and 'systemd') , hence the check fails, causing setup to wrongly assume systemd is absent, t therefore the guest agent service is not created.

[Nageswara Nandigam]

Fixed the issue.