enable the test for running on RHEL-7
    
    The systemd-bootchart service is available on RHEL-7 and it belongs
    to the systemd package. The same service is also available in various
    Fedoras, but it belongs to the systemd-bootchart package.
    The systemd-bootchart service is not available on RHEL-8 at all.
    Now, the automated TC should not end prematurely on relevant operating
    systems.