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 Map<String, List<AliasMetadata>> findAliases(final String[] aliases, final String[] concreteIndices) {
        assert aliases != null;
        assert concreteIndices != null;
        if (concreteIndices.length == 0) {
            return ImmutableOpenMap.of();
        }
        String[] patterns = new String[aliases.length];
        boolean[] include = new boolean[aliases.length];
        for (int i = 0; i < aliases.length; i++) {
            String alias = aliases[i];
            if (alias.charAt(0) == '-') {
                patterns[i] = alias.substring(1);
                include[i] = false;
            } else {
                patterns[i] = alias;
                include[i] = true;
            }
        }
        boolean matchAllAliases = patterns.length == 0;
        ImmutableOpenMap.Builder<String, List<AliasMetadata>> mapBuilder = ImmutableOpenMap.builder();
        for (String index : concreteIndices) {
            IndexMetadata indexMetadata = indices.get(index);
            List<AliasMetadata> filteredValues = new ArrayList<>();
            for (AliasMetadata aliasMetadata : indexMetadata.getAliases().values()) {
                boolean matched = matchAllAliases;
                String alias = aliasMetadata.alias();
                for (int i = 0; i < patterns.length; i++) {
                    if (include[i]) {
                        if (matched == false) {