CloudWatch: Fix running go test with count (#45892) (#45903)

(cherry picked from commit 304185f682)

Co-authored-by: Shirley <4163034+fridgepoet@users.noreply.github.com>

pkg/tsdb/cloudwatch/get_metric_data_executor_test.go

@@ -12,10 +12,10 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-var counter = 1
-
 type cloudWatchFakeClient struct {
 	cloudwatchiface.CloudWatchAPI
+
+	counterForGetMetricDataWithContext int
 }
 
 func (client *cloudWatchFakeClient) GetMetricDataWithContext(ctx aws.Context, input *cloudwatch.GetMetricDataInput, opts ...request.Option) (*cloudwatch.GetMetricDataOutput, error) {
@@ -23,13 +23,13 @@ func (client *cloudWatchFakeClient) GetMetricDataWithContext(ctx aws.Context, in
 	res := []*cloudwatch.MetricDataResult{{
 		Values: []*float64{aws.Float64(12.3), aws.Float64(23.5)},
 	}}
-	if counter == 0 {
+	if client.counterForGetMetricDataWithContext == 0 {
 		nextToken = ""
 		res = []*cloudwatch.MetricDataResult{{
 			Values: []*float64{aws.Float64(100)},
 		}}
 	}
-	counter--
+	client.counterForGetMetricDataWithContext--
 	return &cloudwatch.GetMetricDataOutput{
 		MetricDataResults: res,
 		NextToken:         aws.String(nextToken),
@@ -39,7 +39,7 @@ func (client *cloudWatchFakeClient) GetMetricDataWithContext(ctx aws.Context, in
 func TestGetMetricDataExecutorTest(t *testing.T) {
 	executor := &cloudWatchExecutor{}
 	inputs := &cloudwatch.GetMetricDataInput{MetricDataQueries: []*cloudwatch.MetricDataQuery{}}
-	res, err := executor.executeRequest(context.Background(), &cloudWatchFakeClient{}, inputs)
+	res, err := executor.executeRequest(context.Background(), &cloudWatchFakeClient{counterForGetMetricDataWithContext: 1}, inputs)
 	require.NoError(t, err)
 	require.Len(t, res, 2)
 	require.Len(t, res[0].MetricDataResults[0].Values, 2)