fix: connect database and secret

Author: starlord-daniel

azure-votes-postgresql/manifests/postgres-votes-demo.yaml

@@ -25,7 +25,9 @@ spec:
     name: Standard_D4s_v3
     tier: GeneralPurpose
   administratorLogin: ${USERNAME}
-  administratorLoginPassword: ${PASSWORD}
+  administratorLoginPassword:
+    name: postgres-secret
+    key: PASSWORD
   storage:
     storageSizeGB: 128
 ---
@@ -64,4 +66,4 @@ stringData:
   PASSWORD: "$PASSWORD"
   SERVER:   "$SERVER.postgres.database.azure.com"
   DATABASE: "votedb"
-  PORT:     "5432"
+  PORT:     "5432"