Prior to this change the PrivacyLedger is running to keep a log of private queries, but the ledger is not actually used to compute the (epsilon, delta) guarantees. This CL adds a function to compute the RDP directly from the ledger.
Note I did verify that the tutorial builds and runs with the changes and for the first few iterations prints the same epsilon values as before the change.
PiperOrigin-RevId: 241063532
