reconcile
Completes a staged keyshare, promoting it to the active share used for signing.
keygen, refresh, and import reconcile internally, so this is only needed as a retry when that internal step failed and the share is still staged (a ReconcileStoreDao with a non-null stagedKeyshare). It resumes from the staged share rather than recomputing the key.
Return
the reconciled, now-active keyshare bytes.
Parameters
keyId
the hex-encoded keyId of the staged keyshare.