[DOCS] Rerun agg at the end of manual downsampling example (#95122)

* [DOCS] Rerun agg at the end of manual downsampling example

* Replace 'index' with 'data stream'

* One more 'index'

docs/reference/data-streams/downsampling-manual.asciidoc

@@ -376,7 +376,7 @@ DELETE /sample-01
 ==== View the results
 
 
-Now, re-run your search query:
+Re-run your search query:
 
 [source,console]
 ----
@@ -450,6 +450,51 @@ been calculated: `min`, `max`, `sum`, and `value_count`.
 ----
 // TEST[skip:todo]
 
+You can now re-run the earlier aggregation. Even though the aggregation runs on
+the downsampled data stream that only contains 288 documents, it returns the
+same results as the earlier aggregation on the original data stream.
+
+[source,console]
+----
+GET /sample-01*/_search
+{
+    "size": 0,
+    "aggs": {
+        "tsid": {
+            "terms": {
+                "field": "_tsid"
+            },
+            "aggs": {
+                "over_time": {
+                    "date_histogram": {
+                        "field": "@timestamp",
+                        "fixed_interval": "1d"
+                    },
+                    "aggs": {
+                        "min": {
+                            "min": {
+                                "field": "kubernetes.container.memory.usage.bytes"
+                            }
+                        },
+                        "max": {
+                            "max": {
+                                "field": "kubernetes.container.memory.usage.bytes"
+                            }
+                        },
+                        "avg": {
+                            "avg": {
+                                "field": "kubernetes.container.memory.usage.bytes"
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+----
+// TEST[continued]
+
 This example demonstrates how downsampling can dramatically reduce the number of
 records stored for time series data, within whatever time boundaries you choose.
 It's also possible to perform downsampling on already downsampled data, to