Update templates to use new variable to allow postgres to run on OCP

roles/tower/defaults/main.yml

@@ -32,3 +32,5 @@ tower_postgres_pass: awxpass
 tower_postgres_image: postgres:10
 tower_postgres_storage_request: 8Gi
 tower_postgres_storage_class: ''
+
+tower_postgres_data_path: '/var/lib/postgresql/data/pgdata'

roles/tower/templates/tower_postgres.yaml.j2

@@ -43,13 +43,15 @@ spec:
                 secretKeyRef:
                   name: '{{ meta.name }}-postgres-pass'
                   key: password
+            - name: PGDATA
+              value: '{{ tower_postgres_data_path }}'
           ports:
             - containerPort: 3306
               name: postgres
           volumeMounts:
             - name: postgres
-              mountPath: /var/lib/postgresql/data
-              subPath: data
+              mountPath: '{{ tower_postgres_data_path | dirname }}'
+              subPath: '{{ tower_postgres_data_path | dirname | basename }}'
   volumeClaimTemplates:
     - metadata:
         name: postgres