Automatic merge from submit-queue (batch tested with PRs 48976, 49474, 40050, 49426, 49430)
Use presence of kubeconfig file to toggle standalone mode
Fixes#40049
```release-note
The deprecated --api-servers flag has been removed. Use --kubeconfig to provide API server connection information instead. The --require-kubeconfig flag is now deprecated. The default kubeconfig path is also deprecated. Both --require-kubeconfig and the default kubeconfig path will be removed in Kubernetes v1.10.0.
```
/cc @kubernetes/sig-cluster-lifecycle-misc @kubernetes/sig-node-misc
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