Describe the bug
Initrd networking does not use predictable interface names, but does enable DHCP on the interfaces that are specified by the normal (networking.) configuration.

To Reproduce
Steps to reproduce the behavior:

1. Enable boot.initrd.network
2. Enable predictable interface names (default)
3. Enable useDHCP on one interface
4. Boot to initrd

Expected behavior
DHCP should be used on all interfaces that have DHCP enabled.

Screenshots

Additional context
Add any other context about the problem here.

Metadata
Please run nix run nixpkgs.nix-info -c nix-info -m and paste the result.
I can't because I can not unlock the root drive without networking ;)
But here's the info from another computer running the same channel and kernel:

• system: "x86_64-linux"
• host os: Linux 5.4.0, NixOS, 20.03.20191125.89b2c0b (Markhor)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.4pre20191022_9cac895
• channels(root): "nixos-20.03pre202991.57cf4eb83bc"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module:
- boot.initrd.network

CC @edolstra