kube_override_hostname must be in kubernetes/master role defaults (#3647)

roles/kubernetes/master/defaults/main.yml

@@ -137,3 +137,10 @@ kube_encryption_algorithm: "aescbc"
 
 # You may want to use ca.pem depending on your situation
 kube_front_proxy_ca: "front-proxy-ca.pem"
+
+# If non-empty, will use this string as identification instead of the actual hostname
+kube_override_hostname: >-
+  {%- if cloud_provider is defined and cloud_provider in [ 'aws' ] -%}
+  {%- else -%}
+  {{ inventory_hostname }}
+  {%- endif -%}