35coreos-live: stop overriding NetworkManager-wait-online timeout to 5s

We originally did this in #326 because we wanted to support booting the
live ISO without networking. This was solved on the initramfs side by
the conditional networking work (#426). But for the real root, this was
still useful because if booting the ISO interactively on a system
without any network, or a non-DHCP network, we didn't want the user to
have to wait until the service timed out before getting a shell.

The core issue however is that we're requesting `network-online.target`
at all. It's an "active unit" which means that it's only pulled in the
transaction, possibly delaying boot, if another systemd unit needs it.
And ideally, no service would need it as per:

https://www.freedesktop.org/wiki/Software/systemd/NetworkTarget/

In our case, this unit was fedora-coreos-pinger. We drop that
requirement here:

coreos/fedora-coreos-pinger#41

With that, we no longer pull in `network-online.target` and so no longer
delay reaching the console even if NetworkManager isn't able to get an
active connection for whatever reason. This matches how it works on
traditional Fedora as well.

Having a short timeout actually also had a counterproductive effect in
the automated install case. There, `coreos-installer.service` does pull
in `network-online.target` (which with
coreos/coreos-installer#565 we could consider
dropping as advised by systemd, though we probably should bump the
number of retries some more in that case), but because of the short
timeout, we genuinely may not yet have the network fully up before we
run (see https://bugzilla.redhat.com/show_bug.cgi?id=1967483).

(cherry picked from commit dd54e8c)

overlay.d/05core/usr/lib/dracut/modules.d/35coreos-live/live-generator

@@ -31,8 +31,6 @@ add_requires sysroot.mount     initrd-root-fs.target
 add_requires sysroot-etc.mount initrd-root-fs.target
 add_requires sysroot-var.mount initrd-root-fs.target
 
-add_requires coreos-liveiso-reconfigure-nm-wait-online.service initrd.target
-
 mkdir -p "${UNIT_DIR}/ostree-prepare-root.service.d"
 cat > "${UNIT_DIR}/ostree-prepare-root.service.d/10-live.conf" <<EOF
 # With live PXE there's no ostree= argument on the kernel command line, so

overlay.d/05core/usr/lib/dracut/modules.d/35coreos-live/module-setup.sh

@@ -47,7 +47,4 @@ install() {
 
     install_and_enable_unit "coreos-livepxe-persist-osmet.service" \
         "default.target"
-
-    inst_simple "$moddir/coreos-liveiso-reconfigure-nm-wait-online.service" \
-        "$systemdsystemunitdir/coreos-liveiso-reconfigure-nm-wait-online.service"
 }

tests/kola/misc-ro

@@ -190,3 +190,11 @@ case "$stream" in
         fi
         ;;
 esac
+
+# We shouldn't pull this into the transaction by default. See
+# https://github.com/coreos/fedora-coreos-config/pull/1088
+# https://www.freedesktop.org/wiki/Software/systemd/NetworkTarget/
+if ! systemctl show -p ActiveState network-online.target | grep -q ActiveState=inactive; then
+    fatal "Unit network-online.target shouldn't be active"
+fi
+ok "unit network-online.target inactive"