Ubuntu Chisel images for MS Build of OpenJDK (11, 17, 21)

[brunoborges]

This pull request introduces Dockerfiles to create container images for the Microsoft Build of OpenJDK using Ubuntu Chisel, a lightweight and streamlined version of Ubuntu designed for smaller image sizes.

Key Features

1. Smaller Base Image:

• The adoption of Ubuntu Chisel reduces the overall image size compared to traditional Ubuntu-based images, offering a more efficient alternative.

2. Default Configuration:

• The container runs with root privileges by default and includes a bash shell.
• The default entrypoint is set to the java command, allowing seamless execution of Java applications.

3. Optional Non-Shell User:

• Users have the flexibility to configure the container to run with the app user, a non-privileged user that does not have access to a shell.

Rationale

This PR aims to provide an alternative that strikes a balance between minimalism and usability, catering to users who require a smaller Ubuntu-based image but still need access to a shell for debugging or other purposes.

$  docker git:(ubuntu-chiselled) ✗ docker images | grep ubuntu                                 
mcr.microsoft.com/openjdk/jdk    21-ubuntu-chisel      16a311bf8191   38 minutes ago      169MB
mcr.microsoft.com/openjdk/jdk    17-ubuntu-chisel      3948e6292841   38 minutes ago      156MB
mcr.microsoft.com/openjdk/jdk    11-ubuntu-chisel      220b15004ed8   38 minutes ago      156MB
mcr.microsoft.com/openjdk/jdk    21-ubuntu             aacd344997b6   13 hours ago        673MB
mcr.microsoft.com/openjdk/jdk    17-ubuntu             e5c6ef2ce7c4   13 hours ago        632MB
mcr.microsoft.com/openjdk/jdk    11-ubuntu             380ccaa60052   13 hours ago        613MB

[brunoborges]

This needs more thought. Moving PR back to draft.