[devcontainers] Warn users using Docker Desktop on Linux

• VSCode Version: Any
• Local OS Version: Any
• Remote OS Version: Any
• Remote Extension/Connection Type: Containers

• Logs: N/A

Steps to Reproduce:

1. Try to open any Dev container with Docker Desktop for Linux as the backend

Does this issue occur when you try this locally?: N/A
Does this issue occur when you try this locally and all extensions are disabled?: N/A

This is more of a Docker Desktop on Linux issue, but wanted to mention it here because I feel like maybe VS Code should issue a warning about it? Even repos to test dev containers like vscode-remote-try-node will not work, as Docker Desktop on Linux has an interesting file sharing conundrum. All the files in the container become owned by root, and cannot be edited. A workaround of setting containerUser and/or remoteUser as root might not be a great idea. Maybe if VS Code detects that a Linux user is using Docker Desktop, it should warn about this, proposing some actions to take. Honestly though, who uses Docker Desktop on Linux? 😄