Sample controller: Init flags
Sample controller: Init flags

Without this, the flags to make klog log to stdout are not even shown.
Figuring out the `InitFlags()` is not very intuitive for ppl new to the
project, which is the target audience of the sample-controller.

Kubernetes-commit: 5f610cea1f30a81c2945d5b0f26210cccbd325d3

kubernetes/sample-controller,kubernetes/sample-controller