test if cups-pdf can connect to /run/systemd/userdb/io.systemd.DynamicUser
    
    A recent samba and cups-pdf testing revealed that SELinux prevents
    the cups-pdf processes from connecting to UNIX stream socket:
     * /run/systemd/userdb/io.systemd.DynamicUser (kernel_t)
    
    The TC reproduces the situation.
    
    In order to support the whole cups-pdf functionality, I believe that
    SELinux policy should allow the action. The TC looks for appropriate
    policy rules.
    
    The TC covers BZ#2234765.