Add aws to default_resolver

When VPC is used, external DNS might not be available. This patch change
behavior to use metadata service instead of external DNS when
upstream_dns_servers is not specified.

Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

roles/kubernetes/preinstall/tasks/set_resolv_facts.yml

@@ -16,7 +16,7 @@
       {{dns_domain}}.{{d}}./{{d}}.{{d}}./com.{{d}}./
       {%- endfor %}
     default_resolver: >-
-      {%- if cloud_provider is defined and cloud_provider == 'gce' -%}169.254.169.254{%- else -%}8.8.8.8{%- endif -%}
+      {%- if cloud_provider is defined and cloud_provider in [ 'gce', 'aws' ] -%}169.254.169.254{%- else -%}8.8.8.8{%- endif -%}
 
 - name: check if kubelet is configured
   stat: