Use seconds instead of nanoseconds for the store time layer metrics (#12321)

* Use nanoseconds instead of seconds for the api metrics

* Using seconds instead of nanoseconds in the store layer metrics

store/layer_generators/main.go

@@ -246,14 +246,13 @@ func (s *{{$.Name}}{{$substoreName}}Store) {{$index}}({{$element.Params | joinPa
 	{{ else }}
 	{{$element.Results | genResultsVars}} := s.{{$substoreName}}Store.{{$index}}({{$element.Params | joinParams}})
 	{{ end }}
-	t := timemodule.Now()
-	elapsed := t.Sub(start)
+	elapsed := float64(timemodule.Since(start)) / float64(timemodule.Second)
 	if s.Root.Metrics != nil {
 		success := "false"
 		if {{$element.Results | errorToBoolean}} {
 			success = "true"
 		}
-		s.Root.Metrics.ObserveStoreMethodDuration("{{$substoreName}}Store.{{$index}}", success, float64(elapsed))
+		s.Root.Metrics.ObserveStoreMethodDuration("{{$substoreName}}Store.{{$index}}", success, elapsed)
 	}
 	return {{$element.Results | genResultsVars}}
 }