Add a post-install step that deletes the Deprecated deployments.

[vaikas]

Problem
As part of the #3212 we discussed different ways to clean up the old Deployments. Currently the PR turns the old Deployments to replicas = 0.
Perhaps we should add a post-install job that would actually clean those up properly? Seems like a bigger issue, so opening up an issue to discuss this.

Persona:
Operator

Exit Criteria
Once we have a good upgrade story that we all agree on + implementation.

Time Estimate (optional):
2-3

Additional context (optional)
Add any other context about the feature request here.

[n3wscott]

+1 on : I think we should delete the deployments in a post-install script and drop the files from the repo.

[lberk]

We might also want to make sure we track

• SA's
• Deployments
• CM's

[n3wscott]

/assign