Description of problem:
Customer uses AWS with multiple storage classes, efs and gp2 with efs configured to be default.  When deploying metrics, it will be deployed on efs by default because there is no option to specify what storage class to use.  The customer wants it deployed on gp2.
Customer modified the ansible playbook to specify the storage class.  They feel this was an unnecessary step and would like it implemented as a feature.  
See for more details: https://github.com/openshift/openshift-ansible/compare/release-3.7...mmckinst:storage_class?expand=1

Version-Release number of selected component (if applicable):
OCP 3.7

How reproducible:
Customer verified

Steps to Reproduce:
See https://github.com/openshift/openshift-ansible/compare/release-3.7...mmckinst:storage_class?expand=1 for details provided by customer

Actual results:
Had to alter playbook to specify storage class

Expected results:
Would prefer this be a feature asking to specify

Additional info:
https://github.com/openshift/openshift-ansible/compare/release-3.7...mmckinst:storage_class?expand=1