Moving prompt for NTP options to install_check
    
    In a interactive installation of freeipa server a promt asks for NTP related
    options after install_check has been called. As it may cause confusion to users
    moving to install_check methods where the prompt for other options is being done.
    Refactored sync_time() method to use passed parameters ntp_servers and ntp_pool.
    
    Resolves: https://pagure.io/freeipa/issue/7930
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Oleg Kozlov <okozlov@redhat.com>