metric: update tick in SQL histogram

Previously, we were not performing tick/rotate histogram during persisting
parent histogram metrics. This was resulting higher quantile values for
recorded parent metrics values. This patch introduces changes which make sure
to tick/rotate if next tick time is before current time. This aligned with
existing agg histogram persistence.

Fixes: #145056
Epic: CRDB-43153
Release note: None

Author: aa-joshi

pkg/util/metric/aggmetric/agg_metric.go

@@ -268,6 +268,8 @@ func (sm *SQLMetric) getChildByLabelConfig(
 ) (ChildMetric, bool) {
 	var childMetric ChildMetric
 	switch sm.labelConfig.Load() {
+	case uint64(metric.LabelConfigDisabled):
+		return nil, false
 	case uint64(metric.LabelConfigDB):
 		childMetric = sm.getOrAddChild(f, db)
 		return childMetric, true

pkg/util/metric/aggmetric/histogram.go

@@ -294,6 +294,11 @@ func (sh *SQLHistogram) GetMetadata() metric.Metadata {
 
 // Inspect is part of the metric.Iterable interface.
 func (sh *SQLHistogram) Inspect(f func(interface{})) {
+	func() {
+		sh.ticker.Lock()
+		defer sh.ticker.Unlock()
+		tick.MaybeTick(&sh.ticker)
+	}()
 	f(sh)
 }