test if usbmuxd can access /proc/1/environ file
    
    Recent testing revealed that the usbmuxd service triggers SELinux
    denials during its start. SELinux prevented the usbmuxd process
    from accessing the /proc/1/environ file. The TC reproduces the
    situation.
    
    I believe this access should be dontaudited in SELinux policy,
    because it is not necessary. The TC looks for appropriate policy
    rules.
    
    The TC covers BZ#1959747.