Add option of 60 days to container image cleanup policy

Context

You can use the Container Registry cleanup policy to programmatically keep or delete items in your registry. You can choose to delete image/tags after 7/14/30/90 days.

Problem to solve

The problem is that 30 -> 90 days is quite a large jump. We should have an option for 60 days as a happy medium.

Proposal

Add an option to the cleanup policies that will remove tags after 60 days. This will give Admin more options for how to manage their registries.