Automatic merge from submit-queue (batch tested with PRs 41826, 42405)

Add stubDomains and upstreamNameservers configuration to kube-dns

```release-note
Updates the dnsmasq cache/mux layer to be managed by dnsmasq-nanny.
dnsmasq-nanny manages dnsmasq based on values from the
kube-system:kube-dns configmap:

"stubDomains": {
	"acme.local": ["1.2.3.4"]
},

is a map of domain to list of nameservers for the domain. This is used
to inject private DNS domains into the kube-dns namespace. In the above
example, any DNS requests for *.acme.local will be served by the
nameserver 1.2.3.4.

"upstreamNameservers": ["8.8.8.8", "8.8.4.4"]

is a list of upstreamNameservers to use, overriding the configuration
specified in /etc/resolv.conf.
```