CORD-1441
Install Apache proxy and ElasticStack during physical pod install

Change-Id: I5b16d8916a59baaef41a9b03fe45b3d7126896b0
(cherry picked from commit d85d5a817084a46c783c660ecec903ac08ce59c6)
diff --git a/prep-platform-playbook.yml b/prep-platform-playbook.yml
index 8661208..a195137 100644
--- a/prep-platform-playbook.yml
+++ b/prep-platform-playbook.yml
@@ -32,3 +32,4 @@
     - common-prep
     - { role: cloudlab-prep, when: on_cloudlab }
 
+- include: deploy-elasticstack-playbook.yml