Receive the to-device events that sent to the dehydrated device
The rehydrated device will decrypt the events and pass the room keys
into the OlmMachine.
to_device_events is a JSON-encoded result of the events array from
/dehydrated_device/{device_id}/events.
Returns an array of RoomKeyInfo, indicating the room keys that were
received.
A rehydrated device
This device can receive to-device events to get room keys that were send to it.