If the root is on network, let nm-initrd-generator create configuration
even if none was explicitly specified on the command line.
Also do the same if /tmp/net.ifaces exists, because the anaconda plugin
creates an empty file in that location in hopes that will make us
configure the network.
Look for "connection-uuid" instead of "managed" to determine the devices
that are actually activated with a connection and call the online hook.
This fixes the anaconda-net root mount, which utilizes the online hook.
Lubomir Rintel