Merge pull request #66095 from MrHohn/dns-autoscaler-1.2.0

Automatic merge from submit-queue (batch tested with PRs 66095, 66092). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Bump cluster-proportional-autoscaler to 1.2.0

**What this PR does / why we need it**:
Ref https://github.com/kubernetes-incubator/cluster-proportional-autoscaler/pull/47.

Major changes in cluster-proportional-autoscaler to 1.2.0:
- Watch nodes instead of periodic polls.

RBAC permission is slightly edited to allow dns-autoscaler to watch nodes.

/assign @shyamjvs 
cc @wojtek-t
 
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #NONE

**Release note**:

```release-note
NONE
```

cluster/addons/dns-horizontal-autoscaler/dns-horizontal-autoscaler.yaml

@@ -29,7 +29,7 @@ metadata:
 rules:
   - apiGroups: [""]
     resources: ["nodes"]
-    verbs: ["list"]
+    verbs: ["list", "watch"]
   - apiGroups: [""]
     resources: ["replicationcontrollers/scale"]
     verbs: ["get", "update"]
@@ -82,7 +82,7 @@ spec:
       priorityClassName: system-cluster-critical
       containers:
       - name: autoscaler
-        image: k8s.gcr.io/cluster-proportional-autoscaler-amd64:1.1.2-r2
+        image: k8s.gcr.io/cluster-proportional-autoscaler-amd64:1.2.0
         resources:
             requests:
                 cpu: "20m"