Wire Database:Server/User/PostgresDatabase for staging AppRegIdentity

Author: Christdej

api/appsettings.Staging.json

@@ -17,7 +17,10 @@
   ],
   "Database": {
     "UseInMemoryDatabase": false,
-    "AllowedAuthMethods": [ "AppRegIdentity", "ConnectionString" ]
+    "AllowedAuthMethods": [ "AppRegIdentity", "ConnectionString" ],
+    "Server": "robotics-staging-psql-server",
+    "PostgresDatabase": "sara",
+    "User": "sara-staging"
   },
   "KeyVault": {
     "VaultUri": "https://sarastaging-kv.vault.azure.net/"