Ensure key generation retries after remote key provisioning

Previously, the key pair generation would error out even if we
successfully provisioned attestation keys. Instead, we should retry
key generation after the GenerateRkpKeyService reports an OK status.

Bug: 231495834
Test: RemoteProvisionerUnitTests
Change-Id: I049294cbc7119de55b5de02499bf4609d4c6de5d
Merged-In: I049294cbc7119de55b5de02499bf4609d4c6de5d