test if usbmuxd can call statfs on /sys/fs/cgroup filesystem
    
    Recent testing revealed that the usbmuxd service triggers SELinux
    denials during its start, because SELinux prevents the usbmuxd
    process from accessing the /sys/fs/cgroup filesystem. The TC is
    able to reproduces the situation.
    
    I believe this access should be allowed in SELinux policy. The TC
    looks for appropriate policy rules.
    
    The TC covers BZ#1936705.