test(client-s3): update S3.ispec.ts (#5343)

Author: kuhe

clients/client-s3/test/e2e/S3.ispec.ts

@@ -123,7 +123,7 @@ describe("@aws-sdk/client-s3", () => {
 
     it("should succeed with valid body payload", async () => {
       // prepare the object.
-      const body = createBuffer("16KB");
+      const body = createBuffer("1MB");
 
       try {
         await client.putObject({ Bucket, Key, Body: body });