bugfix: fix proper type of setting maxConcurrentShardRequests (#47120) (#47548)

(cherry picked from commit c0104db72d)

Co-authored-by: Aleksandr Stepanov <alexandrst88@gmail.com>

pkg/tsdb/elasticsearch/elasticsearch.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"strconv"
 
 	"github.com/Masterminds/semver"
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
@@ -95,8 +96,17 @@ func newInstanceSettings() datasource.InstanceFactoryFunc {
 			timeInterval = ""
 		}
 
-		maxConcurrentShardRequests, ok := jsonData["maxConcurrentShardRequests"].(float64)
-		if !ok {
+		var maxConcurrentShardRequests float64
+
+		switch v := jsonData["maxConcurrentShardRequests"].(type) {
+		case float64:
+			maxConcurrentShardRequests = v
+		case string:
+			maxConcurrentShardRequests, err = strconv.ParseFloat(v, 64)
+			if err != nil {
+				maxConcurrentShardRequests = 256
+			}
+		default:
 			maxConcurrentShardRequests = 256
 		}