Attempting to checkout the PR into a dev container fails

[JoelBrenstrum]

This maybe a feature request as im not sure if its intended to work.

Attempting to checkout a PR into a dev container results in a failure due to the incorrect branch name being used

• Extension version: v0.2.2
• VSCode Version: 1.95.3
• OS: M1 Macbook pro 14.1.1 (23B81)

Steps to Reproduce:

1. Right click a PR and select checkout in Dev Container
2. Notice that the suggested volume name is UNIQUE where it should be the branch name
3. Typing anything here will eventually result in a failure when it attempts to checkout the git branch UNIQUE

It appears this option is being injected by the Dev Container extension
https://github.com/Microsoft/vscode-remote-release.git

It would be great for our team if we could do PRs reviews in Dev Containers.