Fix bizarre Swift DeletionPolicy unit tests

If something shouldn't be called... don't tell the mocks to expect it to be
called. We will get UnexpectedMethodCallError if it is.

Change-Id: I61a7b77cb273b42177a37efa98fc62fd69770545
Use PhysName for testing Swift container names

Change-Id: Icc000a9235fcd9ee810581b932ded73319decfee