### 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
/**
         * Return a delegate field type for the default metric sub-field
         * @return a field type
         */
        private NumberFieldMapper.NumberFieldType delegateFieldType() {
            return delegateFieldType(defaultMetric);
        }
        @Override
        public String typeName() {
            return CONTENT_TYPE;
        }
        private void setMetricFields(EnumMap<Metric, NumberFieldMapper.NumberFieldType> metricFields) {
            this.metricFields = metricFields;
        }
        public Map<Metric, NumberFieldMapper.NumberFieldType> getMetricFields() {
            return Collections.unmodifiableMap(metricFields);
        }
        public void addMetricField(Metric m, NumberFieldMapper.NumberFieldType subfield) {
            if (metricFields == null) {
                metricFields = new EnumMap<>(AggregateDoubleMetricFieldMapper.Metric.class);
            }
            if (name() == null) {
                throw new IllegalArgumentException("Field of type [" + typeName() + "] must have a name before adding a subfield");
            }
            metricFields.put(m, subfield);
        }
        public void setDefaultMetric(Metric defaultMetric) {
            this.defaultMetric = defaultMetric;
        }
        Metric getDefaultMetric() {