Move set_facts to kubespray-defaults defaults

These facts can be generated in defaults with a performance
boost.

Also cleaned up duplicate etcd var names.

roles/etcd/templates/etcd.j2

@@ -17,7 +17,5 @@
   {% endif %}
   --name={{ etcd_member_name | default("etcd") }} \
   {{ etcd_image_repo }}:{{ etcd_image_tag }} \
-  {% if etcd_after_v3 %}
-  {{ etcd_container_bin_dir }}etcd \
-  {% endif %}
+  /usr/local/bin/etcd \
   "$@"