### Elasticsearch Version

7.x, 8.x

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

Darwin 

### Problem Description

A data stream must have an index template that matches it in order to exist.
When managing index templates we want to make sure we don't leave a
data stream without a [corresponding index template](https://github.com/elastic/elasticsearch/blob/acf9968f9d397d755d5ad9fcf815cca23bbeda61/server/src/main/java/org/elasticsearch/cluster/metadata/MetadataIndexTemplateService.java#L918).

The `dataStreamsUsingTemplate` check uses the index pattern of the index 
templates to conclude if a template is used by a data stream, however it should
be enhanced to check the priority too as there can only be only one index template
that matches a data stream and it's the one with the highest priority.

### Steps to Reproduce

Create an ILM policy
```
PUT _ilm/policy/testing_yo
{
  "policy": {
    "phases": {
      "warm": {
	"actions": {
	  "shrink": {
          "number_of_shards": 1
	  }
        }
      }
    } 
  }
}
```

Create an index template with the `data_stream` option:
```
PUT _index_template/logs_data_stream
{
	"index_patterns": [ "logs*", "te*", "bar*" ],
	"data_stream": {},
        "priority": 100,
	"template" : {
	  "settings": {
            "index.number_of_shards": 3,
	    "index.lifecycle.name": "testing"
	  }
	}
}
```

Create the data stream
```
POST logs_test/_doc 
{
  "message": "testing",
  "@timestamp": "1591890611"
}
```

Create a new index template that would match this data stream with a higher priority
```
PUT _index_template/higher_logs_data_stream
{
	"index_patterns": [ "logs*", "te*", "bar*" ],
	"data_stream": {},
        "priority": 500,
	"template" : {
	  "settings": {
            "index.number_of_shards": 3,
	    "index.lifecycle.name": "testing"
	  }
	}
}
```

Attempt to delete the previous, lower priority index template:
```
DELETE _index_template/logs_data_stream
```

### Logs (if relevant)

_No response_
modules/data-streams/src/internalClusterTest/java/org/elasticsearch/datastreams/DataStreamIT.java
assertThat(getDataStreamResponse.getDataStreams().size(), equalTo(1));
        DataStreamInfo info = getDataStreamResponse.getDataStreams().get(0);
        assertThat(info.getIndexTemplate(), equalTo("id1"));
        assertThat(info.getDataStreamStatus(), equalTo(ClusterHealthStatus.GREEN));
        assertThat(info.getIlmPolicy(), nullValue());
        DataStream dataStream = info.getDataStream();
        assertThat(dataStream.getName(), equalTo("logs-foobar"));
        assertThat(dataStream.getTimeStampField().getName(), equalTo("@timestamp"));
        assertThat(dataStream.getIndices().size(), equalTo(1));
        assertThat(dataStream.getIndices().get(0).getName(), backingIndexEqualTo("logs-foobar", 1));
        assertThat(dataStream.getMetadata(), equalTo(Map.of("managed_by", "core-features")));
    }
    public void testClusterStateIncludeDataStream() throws Exception {
        putComposableIndexTemplate("id1", List.of("metrics-foo*"));
        CreateDataStreamAction.Request createDataStreamRequest = new CreateDataStreamAction.Request("metrics-foo");
        client().execute(CreateDataStreamAction.INSTANCE, createDataStreamRequest).get();
        
        ClusterStateRequest request = new ClusterStateRequest().indices(".ds-metrics-foo-*000001");
        ClusterState state = client().admin().cluster().state(request).get().getState();
        assertThat(state.metadata().dataStreams().size(), equalTo(1));
        assertThat(state.metadata().dataStreams().get("metrics-foo").getName(), equalTo("metrics-foo"));
    }
    /**
     * Tests that multiple threads all racing to rollover based on a condition trigger one and only one rollover
     */
    public void testMultiThreadedRollover() throws Exception {
        final String dsName = "potato-biscuit";
        putComposableIndexTemplate("id1", List.of("potato-*"));
        ensureGreen();
        final int threadCount = randomIntBetween(5, 10);