[CORD-2889]
Use premade `postgres` container

Change-Id: Ifc9a021c425d8f03c98d566978400884fbace4de
diff --git a/xos-core/templates/db-deployment.yaml b/xos-core/templates/db-deployment.yaml
index f950b32..c103e09 100644
--- a/xos-core/templates/db-deployment.yaml
+++ b/xos-core/templates/db-deployment.yaml
@@ -40,3 +40,12 @@
                 configMapKeyRef:
                   name: xos-db
                   key: service_5432_name
+            - name: POSTGRES_DB
+              value: {{ .Values.configs.core_config.database.name | quote }}
+            - name: POSTGRES_USER
+              value: {{ .Values.configs.core_config.database.username | quote }}
+            - name: POSTGRES_PASSWORD
+              valueFrom:
+                secretKeyRef:
+                  name: xos-db-secret
+                  key: postgres-password