_mvt endpoint does not include cross cluster prefix with `_index` value. For example, `_index` returns `myIndexPattern` instead of expected `cluster_one:myIndexPattern`. _search endpoint includes cross cluster prefix with `_index` value. This is causing problems in [Kibana maps tooltips](https://github.com/elastic/kibana/issues/153210)
x-pack/plugin/vector-tile/src/main/java/org/elasticsearch/xpack/vectortile/rest/RestVectorTileAction.java
VectorTileUtils.addPropertyToFeature(featureBuilder, layerProps, KEY_TAG, bucketKey);
            
            VectorTileUtils.addPropertyToFeature(featureBuilder, layerProps, COUNT_TAG, bucket.getDocCount());
            
            addAggsFields(featureBuilder, layerProps, bucket);
            
            aggLayerBuilder.addFeatures(featureBuilder);
            if (request.getWithLabels()) {
                
                featureBuilder.clear();
                GeoPoint labelPos = (GeoPoint) bucket.getKey();
                byte[] labelPosFeature = featureFactory.point(labelPos.lon(), labelPos.lat());
                if (labelPosFeature != null && labelPosFeature.length != 0) {
                    featureBuilder.mergeFrom(labelPosFeature);
                    VectorTileUtils.addPropertyToFeature(featureBuilder, layerProps, KEY_TAG, bucketKey);
                    VectorTileUtils.addPropertyToFeature(featureBuilder, layerProps, COUNT_TAG, bucket.getDocCount());
                    VectorTileUtils.addPropertyToFeature(featureBuilder, layerProps, LABEL_POSITION_FIELD_NAME, true);
                    addAggsFields(featureBuilder, layerProps, bucket);
                    aggLayerBuilder.addFeatures(featureBuilder);
                }
            }
        }
        VectorTileUtils.addPropertiesToLayer(aggLayerBuilder, layerProps);
        return aggLayerBuilder;
    }
    private static void addAggsFields(
        final VectorTile.Tile.Feature.Builder featureBuilder,
        final MvtLayerProps layerProps,
        final InternalGeoGridBucket bucket
    ) throws IOException {