Import restart_services.yml in buildvm-osbuild.yml playbook
    
    The buildvm-osbuild.yml playbook fails when running the base role,
    specifically when configuring chronyd and restarting it. The reason is
    that the role is notifying a handler, which is not defined in the role,
    but it is defined in the main handlers file restart_services.yml.
    
    Import handlers from restart_services.yml in the buildvm-osbuild.yml
    playbook to ensure that all common handlers are available.
    
    Signed-off-by: Tomáš Hozza <thozza@redhat.com>