Git Branches does not select new branch when switching externally

Steps to reproduce:

• Open the Branches side panel
• Checkout a branch
• Change to another branch or detached head with a command line git command

Result:

• The last checked out branch stays selected
• By using the "refresh" button, the correct branch gets selected

Expected behaviour:

• When checking out another branch, the new branch should be selected
• When checking out detached head, no branch should be selected