Test: Remote Containers settings for attached containers.

[chrmarti]

Testing #1589

• Windows @dbaeumer
• anyOS @deepak1556

Complexity: 2

Use instructions here on how to get a container to attach to.

Test the "settings" property in the configuration for attached containers:

• Note that the config file applies to all containers of an image.
• When the container is attached to for the first time the settings are copied to the container.
• Once the settings have been copied to the container, they are only copied back to the config file.
• Verify that both the initial copying to the container and the updating of the config file after that work.

[deepak1556]

Works well 👍 , identified two issues wrt container workflow.