test(aws-client-api-test): add credentials not called by default

Author: trivikr

private/aws-client-api-test/src/client-credentials-tests/client-credentials-force-refresh.spec.ts

@@ -28,6 +28,9 @@ describe("client credentials forceRefresh", () => {
       "%o",
       async (ClientCtr) => {
         const client = new ClientCtr(config);
+
+        // Credentials function is only called on the first call (done by API call).
+        expect(credentials).not.toHaveBeenCalled();
         await client.config.credentials();
         expect(credentials).toHaveBeenCalledTimes(1);