Enable NetworkManager-wait-online.service to match NetworkManager.service
See https://bugzilla.redhat.com/show_bug.cgi?id=1455704:
instead of NetworkManager.rpm containing a symlink in /usr to enable
NetworkManager-wait-online.service unconditionally, it should be enabled
and disabled in presets together with NetworkManager.service.
This matches what was done for systemd-networkd-wait-online.service in
fccb88b6e14aaf76472b7de7595fbe079b25261e, to match systemd-networkd.service.
Signed-off-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>