Active/Live Remote Kernel instance is not selected after it is started

[sbatten]

While testing #9768, I was quite confused by the kernel picker UI.

1. I select "Python 3" unstarted (the only kernel at the start)
2. I run a cell
3. The kernel picker says the unstarted kernel is the currently selected kernel
4. There is a new entry that is the newly started kernel which is truly the currently selected kernel

Perhaps there is a solution in the proxy/lazy kernel work.

[sbatten]

cc @rchiodo

[rchiodo]

We'd love to be able to update the kernel after we start it. I think if the controller.resolve can return a different controller after it's started, that would make this solvable.