The "add dev container files" quick pick can remove the item you want

[alexr00]

Testing #226686

If your timing is unlucky it's very easy to lose the custom template you pasted in:

1. Open the "add dev container files" quick pick
2. Choose add to workspace
3. Paste in your custom template path
4. See that the quick pick item offers to use your custom template ✅
5. Pause, and see that the quick pick item that offers to use your custom template is removed 🐛