Re-encoding of QR code payloads may produce different results
Since !394 (merged), adding a contact sometimes fails at the confirmation stage.
The Payload class contains a map from TransportIds to BdfLists. When calculating confirmation records, the Payload object received from the contact is re-encoded using the map's iteration order. The map is implemented as a HashMap, which doesn't have a defined iteration order. Devices with different HashMap implementations may re-encode each other's payloads differently from the original encoding, thus producing different confirmation records.