Setting the current droplet for an app should not cause pod restart

[georgethebeatle]

Reproduction steps

• Push an app
• Take record of the cfApp current droplet
• Change the app code and re-push
• Wait for the app to start, then set the current droplet of the cfApp to the recorded value
• The underlying pod will restart

Debugging

When we set the droplet on the app the app controller updates the process with the new build and this build's image propagates all the way down to the spec of the statefulset which (in case the build is different) causes the pod to restart.

This is not how classic CF works. Instead it makes use of the revisions concept so that the user is in control of what is being run and when it is being run.