chore(docs): Replicate custom histograms CHANGELOG to v1.46.0.

In theory v1.44.0 was the first version in which this was fixed, but we
don't recommend running that version for the reasons that are already noted
in the CHANGELOG.md.

Therefore, the first version that we recommend using to utilize custom
historgrams is v1.46.0.  This updates the CHANGELOG.md to signal that with a
note and a duplication of the original CHANGELOG entry.

Original Issue: #4543
Initial PR: #4572
Stabilizing PR: #4771

CHANGELOG.md

@@ -418,11 +418,46 @@ By [@kindermax](https://github.com/kindermax) in https://github.com/apollographq
 
 The router now supports caching responses marked with `private` scope. This caching currently works only on subgraph responses without any schema-level information.
 
-For details about the caching behavior, see [PR #4855](https://github.com/apollographql/router/pull/4855) 
+For details about the caching behavior, see [PR #4855](https://github.com/apollographql/router/pull/4855)
 
 
 By [@Geal](https://github.com/Geal) in https://github.com/apollographql/router/pull/4855
 
+### Add configurable histogram buckets per metric ([Issue #4543](https://github.com/apollographql/router/issues/4543))
+
+> [!NOTE]
+>
+> This feature was introduced in v1.40.0 but was prevented from working best until subsequent fixes in later versions.  Therefore, this v1.46.0 release is the first release in which we recommend its use.
+
+The router supports overriding instrument settings for metrics with [OpenTelemetry views](https://opentelemetry.io/docs/concepts/signals/metrics/#views). You can use views to override default histogram buckets.
+
+Configure views with the `views` option. For example:
+
+```yaml
+telemetry:
+  exporters:
+    metrics:
+      common:
+        service_name: apollo-router
+        views:
+          - name: apollo_router_http_request_duration_seconds # Instrument name you want to edit. You can use wildcard in names. If you want to target all instruments just use '*'
+            unit: "ms" # (Optional) override the unit
+            description: "my new description of this metric" # (Optional) override the description
+            aggregation: # (Optional)
+              histogram:
+                buckets: # Override default buckets configured for this histogram
+                - 1
+                - 2
+                - 3
+                - 4
+                - 5
+            allowed_attribute_keys: # (Optional) Keep only listed attributes on the metric
+            - status
+```
+
+By [@bnjjj](https://github.com/bnjjj) in https://github.com/apollographql/router/pull/4572
+
+
 ### Add support of custom events defined by YAML for telemetry ([Issue #4320](https://github.com/apollographql/router/issues/4320))
 
 Users can now [configure telemetry events via YAML](https://www.apollographql.com/docs/router/configuration/telemetry/instrumentation/events/)
@@ -1475,6 +1510,10 @@ By [@bnjjj](https://github.com/bnjjj) in https://github.com/apollographql/router
 
 ### Add configurable histogram buckets per metric ([Issue #4543](https://github.com/apollographql/router/issues/4543))
 
+> [!NOTE]
+>
+> While this feature was introduced in this v1.40.0 release, it was prevented from working best subsequent fixes in later versions.  We recommend using _at least_ Router v1.46.0 to use this feature.
+
 The router supports overriding instrument settings for metrics with [OpenTelemetry views](https://opentelemetry.io/docs/concepts/signals/metrics/#views). You can use views to override default histogram buckets.
 
 Configure views with the `views` option. For example: