Add secondary DNS server to disable-unbound environment

The Cloudflare DNS we are using in the disable-unbound CI
environment for OpenShift works fine in CI, but my ISP seems to
block it. This makes reproducing that job locally difficult. I had
success with the secondary DNS from Cloudflare, so this patch just
adds that to the resolv.conf.

If we were going to keep this disable-unbound solution for a long
time it would probably be better to have this be a template and
allow user configuration. However, my understanding is that this
is a temporary solution, so investing in complicated patches to
wire in a configuration option that will go away seems like
wasted effort.

Change-Id: I7b93efcd76b651807dff3c18885b8d291feffd3e

ci/environments/disable-unbound.yaml

@@ -54,7 +54,7 @@ outputs:
           ignore_errors: true
         - name: Set resolv.conf
           copy:
-            content: "nameserver 1.1.1.1"
+            content: "nameserver 1.1.1.1\nnameserver 1.0.0.1"
             dest: /etc/resolv.conf
             force: yes
             mode: '0644'