CTS: Unify windows and activities proto dumps (89/n)

Can no longer be put off since we need to redo things for task/stack
merge.

Bug: 80414790
Bug: 143460940
Test: Existing tests pass.
Exempt-From-Owner-Approval: Change to how WM proto work.
Change-Id: I03b51c66e912a60df900099c0069c50e6f58c700