Replace deprecatedPublicIPs with externalIPs for Heapster.

Service heapster-address is not going to be created in automatic way by
kube addon manager because if fails on validating (for kubernetes version > 1.6).
Version 1.6 support externalIPs:
https://v1-6.docs.kubernetes.io/docs/api-reference/v1.6/#service-v1-core

Change-Id: I426eea1031b9228ad54272e77cfed428f4bcdf08
1 file changed