### 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_
test/framework/src/main/java/org/elasticsearch/index/mapper/MapperTestCase.java
private final CheckedConsumer<XContentBuilder, IOException> mapping;
        private final CheckedConsumer<XContentBuilder, IOException> value;
        private final Matcher<String> exceptionMessageMatcher;
        private ExampleMalformedValue(
            CheckedConsumer<XContentBuilder, IOException> mapping,
            CheckedConsumer<XContentBuilder, IOException> value,
            Matcher<String> exceptionMessageMatcher
        ) {
            this.mapping = mapping;
            this.value = value;
            this.exceptionMessageMatcher = exceptionMessageMatcher;
        }
        /**
         * Set the mapping used for this value. If not called the default is
         * {@link MapperTestCase#minimalMapping}.
         */
        public ExampleMalformedValue mapping(CheckedConsumer<XContentBuilder, IOException> newMapping) {
            return new ExampleMalformedValue(newMapping, value, exceptionMessageMatcher);
        }
        /**
         * Match error messages that contain a string.
         */
        public ExampleMalformedValue errorMatches(String contains) {
            return errorMatches(containsString(contains));
        }