Automatic merge from submit-queue (batch tested with PRs 40917, 41181, 41123, 36592, 41183)
Set all node conditions to Unknown when node is unreachable
**What this PR does / why we need it**:
Sets all node conditions to Unknown when node does not report status/unreachable
**Which issue this PR fixes**
fixes https://github.com/kubernetes/kubernetes/issues/36273