Fix TSDBPassthroughIndexingIT

Author: felixbarny

modules/data-streams/src/internalClusterTest/java/org/elasticsearch/datastreams/TSDBIndexingIT.java

@@ -327,7 +327,14 @@ public void testTsdbTemplatesNoKeywordFieldType() throws Exception {
             ComposableIndexTemplate.builder()
                 .indexPatterns(List.of("k8s*"))
                 .template(
-                    new Template(Settings.builder().put("index.mode", "time_series").build(), new CompressedXContent(mappingTemplate), null)
+                    new Template(
+                        Settings.builder()
+                            .put("index.mode", "time_series")
+                            .put("index.routing_path", randomBoolean() ? "metricset" : null)
+                            .build(),
+                        new CompressedXContent(mappingTemplate),
+                        null
+                    )
                 )
                 .dataStreamTemplate(new ComposableIndexTemplate.DataStreamTemplate(false, false))
                 .build()

modules/data-streams/src/internalClusterTest/java/org/elasticsearch/datastreams/TSDBPassthroughIndexingIT.java

@@ -184,7 +184,8 @@ public void testIndexingGettingAndSearching() throws Exception {
 
         // validate index:
         var getIndexResponse = client().admin().indices().getIndex(new GetIndexRequest(TEST_REQUEST_TIMEOUT).indices(index)).actionGet();
-        assertThat(getIndexResponse.getSettings().get(index).hasValue("index.routing_path"), equalTo(false));
+        assertThat(getIndexResponse.getSettings().get(index).get("index.routing_path"), equalTo("[attributes.*]"));
+        assertThat(getIndexResponse.getSettings().get(index).get("index.dimensions"), equalTo("[attributes.*]"));
         // validate mapping
         var mapping = getIndexResponse.mappings().get(index).getSourceAsMap();
         assertMap(