Kubernetes: Custom second scheduler container unable to start
In your manifest, you should set the spec.containers[0].livenessProbe.httpGet.scheme to HTTP not HTTPS.
This is because you use the option --port=10251. As the documentation said, you should not use the deprecated --port option anymore, because it expose the API insecurely.
You should set the following options: --port=0 --secure-port=10251 and then you would be able to set the spec.containers[0].livenessProbe.httpGet.scheme to HTTPS.