fix(util-user-agent-node): appId config file name correction (#6729)

* chore(util-user-agent-node): appId config file name correction

* chore(util-user-agent-node): add deprecated name

* chore(util-user-agent-node): deprecated annotation

* chore(util-user-agent-node): remove export

packages/util-user-agent-node/src/nodeAppIdConfigOptions.ts

@@ -1,6 +1,5 @@
-import { LoadedConfigSelectors } from "@smithy/node-config-provider";
 import { DEFAULT_UA_APP_ID } from "@aws-sdk/middleware-user-agent";
-
+import { LoadedConfigSelectors } from "@smithy/node-config-provider";
 
 /**
  * @internal
@@ -10,13 +9,18 @@ export const UA_APP_ID_ENV_NAME = "AWS_SDK_UA_APP_ID";
 /**
  * @internal
  */
-export const UA_APP_ID_INI_NAME = "sdk-ua-app-id";
+export const UA_APP_ID_INI_NAME = "sdk_ua_app_id";
+
+/**
+ * @deprecated
+ */
+const UA_APP_ID_INI_NAME_DEPRECATED = "sdk-ua-app-id";
 
 /**
  * @internal
  */
 export const NODE_APP_ID_CONFIG_OPTIONS: LoadedConfigSelectors<string | undefined> = {
   environmentVariableSelector: (env) => env[UA_APP_ID_ENV_NAME],
-  configFileSelector: (profile) => profile[UA_APP_ID_INI_NAME],
+  configFileSelector: (profile) => profile[UA_APP_ID_INI_NAME] ?? profile[UA_APP_ID_INI_NAME_DEPRECATED],
   default: DEFAULT_UA_APP_ID,
 };