missing netplan config in recent focal minfs tarballs

[sarnold]

Seems like connman went away(?) and the recent ubuntu rootfs (specifically ai) stopped configuring ethernet and I get the exact same behavior using latest with armv7-multiplatform kernels with ubuntu focal rootfs on anything. The fix is adding the netplan (yaml) config => using dhcp/eth0 works fine. I also pretty much always add net.ifnames=0 to cmdline.

Lastly, please don't kill ubuntu rootfs, upstream "cloud" image for armv7 is a joke, and yours gets used for testing arm boards/kernels and chromebooks...