Automatic merge from submit-queue (batch tested with PRs 47896, 50678, 50620, 50631, 51005)
allow heapster option defaults to be set - kubectl top node|pod
**Release note**:
```release-note
NONE
```
Allows downstream / outside consumers of `NewCmdTopNode` and `NewCmdTopPod` commands to set project or case-specific heapster option defaults.
Related downstream PR: https://github.com/openshift/origin/pull/15764
cc @fabianofranz