Support windows containers base image nanoserver:2004

[prabh-62]

Thread continued from dotnet/dotnet-docker#2257

I created an ASP.NET 5 web api with .NET 5 RC1 SDK and created a docker image with self-contained version of web API.

Total size of docker image - 262 MB (nanoserver:2004) + 41 MB (self-container .NET 5 web API)

Tried to deploy with latest nanoserver base image(2004) on ACI (in East US region) and I get UnsupportedWindowsVersion error

FROM mcr.microsoft.com/windows/nanoserver:2004

Then, I tried with 1909 version, and got the same error on Azure Portal - UnsupportedWindowsVersion

FROM mcr.microsoft.com/windows/nanoserver:1909

Then with 1903, same error - UnsupportedWindowsVersion

FROM mcr.microsoft.com/windows/nanoserver:1903

Then downgraded further to 1809, and now I can't even run the API locally.

FROM mcr.microsoft.com/windows/nanoserver:1809

> docker run -p 8080:80 paymentsapp
Failed to map file. CreateFileMappingW(C:\app\PaymentsService.exe) failed with error 5
Failure processing application bundle.
Failed to map bundle file [C:\app\paymentsservice.runtimeconfig.json]

Continued downgrading further and now tried sac2016 version

FROM mcr.microsoft.com/windows/nanoserver:sac2016

And eventually, this base image worked and API successfully ran on ACI - http://paymentsapp.eastus.azurecontainer.io/api/health/stats

However, the deployed image size is 1.21 GB (Trying to keep image as small as 200 MB)
> docker history paymentsapp

IMAGE               CREATED             CREATED BY                                      SIZE                COMMENT
057ff3bd64f9        14 minutes ago      cmd /S /C #(nop)  ENTRYPOINT ["PaymentsServi…   41kB                
a8dabe8d62c8        14 minutes ago      cmd /S /C #(nop)  ENV DOTNET_RUNNING_IN_CONT…   41kB                
e0d49c798106        14 minutes ago      cmd /S /C #(nop)  ENV ASPNETCORE_URLS=http:/…   41kB                
129d6af5de48        14 minutes ago      cmd /S /C #(nop) COPY dir:753a5af31fb0b8f097…   41.9MB              
7849868f555d        14 minutes ago      cmd /S /C #(nop) WORKDIR C:\app                 41kB                
4c872414bf9d        23 months ago       Install update 10.0.14393.2551                  470MB               
<missing>           2 years ago         Apply image 10.0.14393.0                        701MB   

When can we deploy docker images with nanoserver:2004 on ACI?