apiserver: introduce larger buckets for flowcontrol request_wait_duration_seconds bucket

Signed-off-by: Andrew Sy Kim <andrewsy@google.com>

staging/src/k8s.io/apiserver/pkg/util/flowcontrol/metrics/metrics.go

@@ -47,7 +47,7 @@ const (
 
 var (
 	queueLengthBuckets            = []float64{0, 10, 25, 50, 100, 250, 500, 1000}
-	requestDurationSecondsBuckets = []float64{0, 0.005, 0.02, 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, 30}
+	requestDurationSecondsBuckets = []float64{0, 0.005, 0.02, 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, 15, 30}
 )
 
 var registerMetrics sync.Once

test/instrumentation/documentation/documentation-list.yaml

@@ -3612,6 +3612,7 @@
   - 2
   - 5
   - 10
+  - 15
   - 30
 - name: seat_fair_frac
   subsystem: flowcontrol