A composable index template with no `template` defined in the body is mistakingly always assumed to not be a time series template. Even if it refers to a component template that has the `index.mode` setting set to `time_series` and the component template defines mappings with dimension fields or routing paths.

Incorrectly this causes to create a data stream with a tsdb index *without* time series start and end time settings set. The fact that this can happen is another bug and is being tracked #98833.

What should happen in this case is that a tsdb data stream is created with a valid tsdb backing index (with correctly generated time series start and end time settings).

This bug was found as part investigating #98792 and is the cause of that bug.
server/src/main/java/org/elasticsearch/cluster/metadata/Metadata.java
}
        public Builder hashesOfConsistentSettings(DiffableStringMap hashesOfConsistentSettings) {
            this.hashesOfConsistentSettings = hashesOfConsistentSettings;
            return this;
        }
        public Builder hashesOfConsistentSettings(Map<String, String> hashesOfConsistentSettings) {
            this.hashesOfConsistentSettings = new DiffableStringMap(hashesOfConsistentSettings);
            return this;
        }
        public Builder version(long version) {
            this.version = version;
            return this;
        }
        public Builder clusterUUID(String clusterUUID) {
            this.clusterUUID = clusterUUID;
            return this;
        }
        public Builder clusterUUIDCommitted(boolean clusterUUIDCommitted) {
            this.clusterUUIDCommitted = clusterUUIDCommitted;
            return this;
        }
        public Builder generateClusterUuidIfNeeded() {
            if (clusterUUID.equals(UNKNOWN_CLUSTER_UUID)) {
                clusterUUID = UUIDs.randomBase64UUID();
            }
            return this;
        }
        /**
         * @return a new <code>Metadata</code> instance
         */