stats: allow custom histogram buckets (#2800)

* stats: allow custom histogram buckets

Signed-off-by: Kuat Yessenov <[email protected]>

* fix docs

Signed-off-by: Kuat Yessenov <[email protected]>

* fix

Signed-off-by: Kuat Yessenov <[email protected]>

---------

Signed-off-by: Kuat Yessenov <[email protected]>

Author: kyessenov

annotation/annotations.gen.go

@@ -199,6 +199,14 @@ annotations:
     resources:
       - Pod
 
+  - name: sidecar.istio.io/statsHistogramBuckets
+    featureStatus: Alpha
+    description: Specifies the custom histogram buckets with a prefix matcher to separate the Istio mesh metrics from the Envoy stats, e.g. `{"istio":[1,5,10,50,100,500,1000,5000,10000],"envoy":[1,5,10,25,50,100,250,500,1000,2500,5000,10000]}`. Default buckets are `[0.5,1,5,10,25,50,100,250,500,1000,2500,5000,10000,30000,60000,300000,600000,1800000,3600000]`.
+    deprecated: false
+    hidden: false
+    resources:
+      - Pod
+
   - name: sidecar.istio.io/userVolume
     featureStatus: Alpha
     description: Specifies one or more user volumes (as a JSON array) to be added to
@@ -467,7 +475,7 @@ annotations:
 
   - name: sidecar.istio.io/extraStatTags
     featureStatus: Alpha
-    description: An additional list of tags to extract from the in-proxy Istio telemetry. each additional tag needs to be present in this list.
+    description: An additional list of tags to extract from the in-proxy Istio Wasm telemetry. Each additional tag needs to be present in this list.
     deprecated: false
     hidden: false
     resources:
@@ -521,4 +529,4 @@ annotations:
     deprecated: false
     hidden: true
     resources:
-      - Any
+      - Any