add cloudwatch region (#7161)

pkg/api/cloudwatch/metrics.go

@@ -140,8 +140,8 @@ func init() {
 // Please update the region list in public/app/plugins/datasource/cloudwatch/partials/config.html
 func handleGetRegions(req *cwRequest, c *middleware.Context) {
 	regions := []string{
-		"ap-northeast-1", "ap-northeast-2", "ap-southeast-1", "ap-southeast-2", "ca-central-1", "cn-north-1",
-		"eu-central-1", "eu-west-1", "eu-west-2", "sa-east-1", "us-east-1", "us-west-1", "us-west-2", "us-gov-west-1",
+		"ap-northeast-1", "ap-northeast-2", "ap-southeast-1", "ap-southeast-2", "ap-south-1", "ca-central-1", "cn-north-1",
+		"eu-central-1", "eu-west-1", "eu-west-2", "sa-east-1", "us-east-1", "us-east-2", "us-gov-west-1", "us-west-1", "us-west-2",
 	}
 
 	result := []interface{}{}