An integrated validator can approve or revoke peers outside a login or
sync, for example during a periodic EDR sync. Only revocations of SSO
peers reached anyone; a newly approved peer kept its empty map, and its
peers did not see it, until an unrelated update or a reconnect.
Add SetPeerValidationChangeListener to the IntegratedValidator interface.
The account manager registers a handler that resolves the affected peers
and calls OnPeersUpdated, the same path a login-time approval takes. The
OSS validator and the mock implement it as a no-op.
