Treat enable_debug in Ansible as a bool

Without the extra bool this when block gets evaluated as a string.
Given that it is always present this means enable_debug has been
enabled regardless of the end user setting.

Change-Id: I9f53f3bca4a6862966e558ea20fe001eabda7bcf
Closes-bug: #1754481

common/deploy-steps-tasks.yaml

@@ -134,7 +134,7 @@
     - name: Set host puppet debugging fact string
       set_fact:
         host_puppet_config_debug: "--debug --verbose"
-      when: enable_debug|default(false)
+      when: enable_debug|default(false)|bool
     - name: Write the config_step hieradata
       copy: content="{{dict(step=step|int)|to_json}}" dest=/etc/puppet/hieradata/config_step.json force=true mode=0600
       become: true