Customer reported that they have seen cases of migrating our stage pods from a failed prior run.  Let's guard against migrating our own resources from a failed/prior run.

Example:

1) Migration-#1 proceeds and fails, it created stage pods and leaves them on source

2) Prior MigPlan is deleted and a new one is recreated

3) Migration-#2 runs and consider the existing stage pods from Migration-#1 as part of the 'source' of that application and wants to preserve them and migrate