Ceph » rgw

Currently if both prefix & suffix filter rules are set and if try to do a `radosgw-admin notification get` & capture the json output it complains incorrect json, as there are multiple keys with same name. The key name for prefix and suffix is same `FilterRule`. As per aws doc, filter rule is a repeated xml tag, and those tags are converted to key for json, however for json the key needs to be unique. So change the layout of FilterRule and make it a array.While setting the Rules and sending the s3 request, the rules are send as array, so return the rules as array as well.
For example this is the output when both prefix and suffix are set for S3Key, and when its captured in json string it complains about same key

                "S3Key": {
                    "FilterRule": {
                        "Name": "prefix",
                        "Value": "health" 
                    },
                    "FilterRule": {
                        "Name": "suffix",
                        "Value": "old" 
                    }
                },