etcd-preinstall job/ container needs to be able to mount etcd cert in case of secure etcd

[sathyan316]

Is this a BUG REPORT or FEATURE REQUEST?:
BUG report

What happened:
etcd-preinstall-hook fails when using secure etcd

What you expected to happen:
helm chart should be able to handle secure etcd. etcd-preinstall container needs to mount etcd cert(s) specifiec in values.yaml

How to reproduce it (as minimally and precisely as possible):
install the helm chart by using secure etcd

Anything else we need to know?:

Environment:

• Container Orchestrator and version:
  docker 1.12, kubernetes (RKE) 1.8.7
• Cloud provider or hardware configuration:
  VMware ESXi 6.0U2
• OS (e.g. from /etc/os-release):
  CoreOS
• Kernel (e.g. uname -a):
  4.13.9
• Install tools:
• Others: