• Extension version: 0.5.0
• VSCode Version: 1.32.1
• OS: macOS 10.14.3

Steps to Reproduce:

1. Click "Exit Review Mode" in a PR description.
2. You will need to choose the relevant repo in a multi-folder workspace (Separate issue Exit PR: No need to ask for which repo in a multi-root setup #654)
3. Choose a different branch.
4. The pull request remains in the status bar and still has a check mark in the pull requests view, if you switch back to the branch you will still be in review mode.

It makes sense for the pull request to be "deselected", that is, for it to disappear from the status bar and the check mark removed from the pull requests view. The same state you start in before you enter review mode. Might even make sense for this to not require switching a branch. Just "exit review mode" so you are back to the same state as checking out the branch normally.