### 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/test/java/org/elasticsearch/xpack/aggregatemetric/mapper/AggregateDoubleMetricFieldMapperTests.java
METRICS_FIELD,
            fieldMapping(this::minimalMapping),
            fieldMapping(
                b -> {
                    b.field("type", CONTENT_TYPE)
                        .field(METRICS_FIELD, new String[] { "min", "max", "value_count", "sum" })
                        .field(DEFAULT_METRIC, "min");
                }
            )
        );
    }
    @Override
    protected Object getSampleValueForDocument() {
        return Map.of("min", -10.1, "max", 50.0, "value_count", 14);
    }
    @Override
    protected Object getSampleValueForQuery() {
        return 50.0;
    }
    @Override
    protected boolean supportsStoredFields() {
        return false;
    }
    /**
     * Test parsing field mapping and adding simple field
     */
    public void testParseValue() throws Exception {
        DocumentMapper mapper = createDocumentMapper(fieldMapping(this::minimalMapping));
        ParsedDocument doc = mapper.parse(
            source(b -> b.startObject("field").field("min", -10.1).field("max", 50.0).field("value_count", 14).endObject())