Automatic merge from submit-queue
[CRI] Use DNSOptions passed by CRI in dockershim.
When @xlgao-zju is working on the CRI validation test, he found that dockershim is not using the DNSOptions passed in CRI. https://github.com/kubernetes-incubator/cri-tools/pull/30#issuecomment-290644357
This PR fixed the issue. I've manually tried, for `ClusterFirst` DNSPolicy, the resolv.conf will be:
```
nameserver 8.8.8.8
search corp.google.com prod.google.com prodz.google.com google.com
options ndots:5
```
For `Default` DNSPolicy, the resolv.conf will be:
```
nameserver 127.0.1.1
search corp.google.com prod.google.com prodz.google.com google.com
```
@xlgao-zju You should be able to test after this PR is merged.
/cc @yujuhong @feiskyer
6c6f4f0185