Remove legacy policy.json file

If there is no policy override configured, but a policy.json
file is present, then it's likely left over from a previous
build. To ensure that we do not carry legacy configuration
files which override the policy-in-code we remove the legacy
file. This is done on restart to ensure that the policy still
applies until the code is updated.

Change-Id: I7faade8b736e9722e986909dd688b628d2cc65e0

handlers/main.yml

@@ -21,3 +21,12 @@
   with_items: "{{ filtered_barbican_services }}"
   listen:
     - "venv changed"
+
+- name: Remove legacy policy.json file
+  file:
+    path: "/etc/barbican/policy.json"
+    state: absent
+  when:
+    - barbican_policy_overrides == {}
+  listen:
+    - Restart barbican services