Disable old ORA on sandboxes by default.

playbooks/edx_sandbox.yml

@@ -18,6 +18,7 @@
     # These should stay false for the public AMI
     COMMON_ENABLE_DATADOG: False
     COMMON_ENABLE_SPLUNKFORWARDER: False
+    ENABLE_LEGACY_ORA: !!null
   roles:
     - role: nginx
       nginx_sites:
@@ -38,7 +39,8 @@
     - elasticsearch
     - forum
     - { role: "xqueue", update_users: True }
-    - ora
+    - role: ora
+      when: ENABLE_LEGACY_ORA
     - certs
     - edx_ansible
     - role: datadog