Add test to verify "device not registered" RKP behavior

This additional test finishes up coverage of the API changes around
retry on rkp-only devices by ensuring unregistered devices correctly
recognize the response from the RKP backend and do not retry.

Bug: 227306369
Test: RemoteProvisionerUnitTests
Change-Id: I6097c9c96a7aa9b4c5ef2ce5c2655aad42d7137d
2 files changed