### 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 EnumSet<Metric> METRICS = EnumSet.noneOf(Metric.class);
    }
    public static class Builder extends FieldMapper.Builder {
        private final Parameter<Map<String, String>> meta = Parameter.metaParam();
        private final Parameter<Boolean> ignoreMalformed;
        private final Parameter<EnumSet<Metric>> metrics = new Parameter<>(Names.METRICS, false, () -> Defaults.METRICS, (n, c, o) -> {
            @SuppressWarnings("unchecked")
            List<String> metricsList = (List<String>) o;
            EnumSet<Metric> parsedMetrics = EnumSet.noneOf(Metric.class);
            for (String s : metricsList) {
                try {
                    Metric m = Metric.valueOf(s);
                    parsedMetrics.add(m);
                } catch (IllegalArgumentException e) {
                    throw new IllegalArgumentException("Metric [" + s + "] is not supported.", e);
                }
            }
            return parsedMetrics;
        }, m -> toType(m).metrics, XContentBuilder::enumSet, Objects::toString).addValidator(v -> {
            if (v == null || v.isEmpty()) {
                throw new IllegalArgumentException("Property [" + Names.METRICS + "] is required for field [" + name() + "].");
            }
        });
        /**
         * Parameter that marks this field as a time series metric defining its time series metric type.
         * For {@link AggregateDoubleMetricFieldMapper} fields gauge, counter and summary metric types are
         * supported.