MB-60425: _prometheusMetrics is meant to only advertise process-level stats

This will keep the list of stats advertised by _prometheusMetrics
and _prometheusMetricsHigh non-overlapping.

Change-Id: Iff10e519b684aff98a1fdc949b356e1b2b4f9749
Reviewed-on: https://review.couchbase.org/c/cbft/+/203870
Well-Formed: Build Bot <[email protected]>
Reviewed-by: <[email protected]>
Tested-by: Abhi Dangeti <[email protected]>

Author: abhinavdangeti

prometheus.go

@@ -247,14 +247,7 @@ func (h *PrometheusMetricsHandler) ServeHTTP(w http.ResponseWriter,
 	w.Header().Set("Cache-Control", "no-cache")
 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 
-	stats, err := gatherIndexesStats(h.mgr, rd, false)
-	if err != nil {
-		rest.ShowError(w, req, fmt.Sprintf("error in retrieving defs: %v", err),
-			http.StatusInternalServerError)
-		return
-	}
-
-	topLevelStats := stats[""]
+	topLevelStats := gatherTopLevelStats(h.mgr, rd)
 
 	for k, v := range topLevelStats {
 		b, err := json.Marshal(v)