Improve comment about US-EAST-1 fix

Author: edouarda

cloud/aws/aws_s3.cc

@@ -481,12 +481,20 @@ Status S3StorageProvider::CreateBucket(const std::string& bucket) {
   Aws::S3::Model::BucketLocationConstraint bucket_location = Aws::S3::Model::
       BucketLocationConstraintMapper::GetBucketLocationConstraintForName(
           ToAwsString(env_->GetCloudEnvOptions().dest_bucket.GetRegion()));
-  // to create a bucket in US-EAST-1 you must specify no constraint location for
-  // legacy reasons
+  //
+  // If you create a bucket in US-EAST-1, no location constraint should be
+  // specified
+  //
+  // https://docs.aws.amazon.com/AmazonS3/latest/API/API_CreateBucket.html
+  //
+  // By default, the bucket is created in the US East (N. Virginia) Region.
+  // You can optionally specify a Region in the request body. You might choose
+  // a Region to optimize latency, minimize costs, or address regulatory
+  // requirements.
+  //
   if ((bucket_location != Aws::S3::Model::BucketLocationConstraint::NOT_SET) &&
       (bucket_location !=
        Aws::S3::Model::BucketLocationConstraint::us_east_1)) {
-    // only set the location constraint if it's not not set
     conf.SetLocationConstraint(bucket_location);
   }