AWS: add OpenSearch to AWS services (#40290) (#40297)

(cherry picked from commit 24af3593a2)

pkg/models/datasource.go

@@ -18,6 +18,7 @@ const (
 	DS_ACCESS_DIRECT  = "direct"
 	DS_ACCESS_PROXY   = "proxy"
 	DS_ES_OPEN_DISTRO = "grafana-es-open-distro-datasource"
+	DS_ES_OPENSEARCH  = "grafana-opensearch-datasource"
 )
 
 var (

pkg/models/datasource_cache.go

@@ -282,7 +282,7 @@ func ClearDSDecryptionCache() {
 
 func awsServiceNamespace(dsType string) string {
 	switch dsType {
-	case DS_ES, DS_ES_OPEN_DISTRO:
+	case DS_ES, DS_ES_OPEN_DISTRO, DS_ES_OPENSEARCH:
 		return "es"
 	case DS_PROMETHEUS:
 		return "aps"