Description of problem:
Code error of resources.limits.memory for prometheus prom-proxy container

Set resource limits for oauth_proxy
openshift_prometheus_oauth_proxy_cpu_limit=200m
openshift_prometheus_oauth_proxy_memory_limit=200Mi
openshift_prometheus_oauth_proxy_cpu_requests=200m
openshift_prometheus_oauth_proxy_memory_requests=200Mi

Get following pod info, resources.limits.memory is not shown in prom-proxy container.
containers
name: prom-proxy
ports:
- containerPort: 8443
name: web
protocol: TCP
resources:
limits:
cpu: 200m
requests:
cpu: 200m
memory: 200Mi

name: alerts-proxy
ports:
- containerPort: 9443
name: web
protocol: TCP
resources:
limits:
cpu: 200m
memory: 200Mi
requests:
cpu: 200m
memory: 200Mi


Checked code in https://github.com/openshift/openshift-ansible/blob/master/roles/openshift_prometheus/templates/prometheus_deployment.j2#L41
it should be
{% if openshift_prometheus_oauth_proxy_memory_limit is defined and openshift_prometheus_oauth_proxy_memory_limit is not none %}

Version-Release number of selected component (if applicable):
# rpm -qa | grep openshift-ansible
openshift-ansible-3.7.0-0.126.4.git.0.3fc2b9b.el7.noarch
openshift-ansible-roles-3.7.0-0.126.4.git.0.3fc2b9b.el7.noarch
openshift-ansible-docs-3.7.0-0.126.4.git.0.3fc2b9b.el7.noarch
openshift-ansible-callback-plugins-3.7.0-0.126.4.git.0.3fc2b9b.el7.noarch
openshift-ansible-filter-plugins-3.7.0-0.126.4.git.0.3fc2b9b.el7.noarch
openshift-ansible-playbooks-3.7.0-0.126.4.git.0.3fc2b9b.el7.noarch
openshift-ansible-lookup-plugins-3.7.0-0.126.4.git.0.3fc2b9b.el7.noarch


How reproducible:
Always

Steps to Reproduce:
1. Set resource limits for oauth_proxy in inventory file and deploy prometheus.
2.
3.

Actual results:
Missed resources.limits.memory for prom-proxy container.

Expected results:
resources.limits.memory should be in prom-proxy container.

Additional info: