Description of problem:
Using ansible to uninstall metrics fail "'dict object' has no attribute 'files'"

Version-Release number of selected component (if applicable):
openshift v3.5.0.7+390ef18
metrics 3.5

How reproducible:
always

Steps to Reproduce:
1. install httpd-tools on master and install java on ansible control machine, have metircs deployed.

# oc get pod -n openshift-infra
NAME                         READY     STATUS    RESTARTS   AGE
hawkular-cassandra-1-lrzsm   1/1       Running   0          35m
hawkular-metrics-dzgz1       1/1       Running   0          35m
heapster-vqmzl               1/1       Running   0          35m

2. prepare inventory file, set openshift_metrics_install_metrics=false

[oo_first_master]
$MASTER ansible_user=root ansible_ssh_user=root ansible_ssh_private_key_file="$PEM" openshift_public_hostname=$MASTER

[oo_first_master:vars]
deployment_type=openshift-enterprise
openshift_release=v3.5.0
openshift_metrics_install_metrics=false

openshift_metrics_hawkular_hostname=hawkular-metrics.$SUBDOMAIN
openshift_metrics_image_prefix=registry.ops.openshift.com/openshift3/
openshift_metrics_image_version=3.5.0

3. checkout openshift-ansible(due to previous bug, I'm using dev's branch )
  #git clone https://github.com/jcantrill/openshift-ansible
  #git checkout bz_1414477_missing_import_jks_deuce

4. ansible-playbook -vvv -i ~/inventory   playbooks/common/openshift-cluster/openshift_metrics.yml

Actual results:
task abort
TASK [openshift_metrics : slurp] ***********************************************
task path: /root/openshift-ansible/roles/openshift_metrics/tasks/install_metrics.yaml:27
fatal: [                          ]: FAILED! => {
    "failed": true, 
    "msg": "'dict object' has no attribute 'files'"
}
	to retry, use: --limit @/root/openshift-ansible/playbooks/common/openshift-cluster/openshift_metrics.retry

PLAY RECAP *********************************************************************
$MASTER : ok=10   changed=0    unreachable=0    failed=1   


Expected results:
Task finish and Metrics is cleaned.

Additional info:
Ansible task log is attached.