### Elasticsearch Version

main

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

all

### Problem Description

When you configure an `aggregate_metric_double` with `ignore_malformed: true` and send a malformed value we create an `_ignored` field with three values, `field.value_count`, `field.min`, and `field.max`. This is the only top "composite" field that creates `_ignored` values for its children. Things like shape only create `field` in `_ignored`. Is there a good reason for `aggregate_metric_double` to be different?

### Steps to Reproduce

see above

### Logs (if relevant)

_No response_
x-pack/plugin/mapper-aggregate-metric/src/main/java/org/elasticsearch/xpack/aggregatemetric/mapper/AggregateDoubleMetricFieldMapper.java
public static final String IGNORE_MALFORMED = "ignore_malformed";
        public static final String METRICS = "metrics";
        public static final String DEFAULT_METRIC = "default_metric";
    }
    /**
     * Enum of aggregate metrics supported by this field mapper
     */
    public enum Metric {
        min,
        max,
        sum,
        value_count
    }
    public static class Defaults {