Abstract 6.3 changes into a separate task to reduce all of the jinja one

liner complexity

Set ES_PATH_CONF when installing so upgrading from 6.2 to 6.3 works as
expected

tasks/elasticsearch-Debian.yml

@@ -36,6 +36,8 @@
   when: es_use_repository
   register: debian_elasticsearch_install_from_repo
   notify: restart elasticsearch
+  environment:
+    ES_PATH_CONF: "/etc/elasticsearch"
 
 - name: Debian - Include versionlock
   include: elasticsearch-Debian-version-lock.yml