EdgeAgent Pull Images via Managed Identity

[cedihegi]

When running iotedge on an Azure VM or an Azure Arc VM, I would expect to be able to pull images from an ACR using the machine's managed identity.
I looked through the documentation and a little bit of source code, is it correct that this is currently not supported?

I dislike the idea of storing credentials in plaintext as it is currently done and in general it would simplify some things if this was an option. Since this is an Azure solution, it seems like the most idiomatic way of accessing a private ACR from azure machines.