CloudWatch: Use the correct metric name for errors per function panel in the AWS Lambda sample dashboard (#110718)

CloudWatch: Use the correct metric name for errors per function panel

public/app/plugins/datasource/cloudwatch/dashboards/Lambda.json

@@ -678,7 +678,7 @@
               "expression": "REMOVE_EMPTY(SEARCH('{AWS/Lambda,FunctionName} MetricName=\"Errors\"', 'Sum', $period))/$period",
               "id": "",
               "matchExact": true,
-              "metricName": "Invocations",
+              "metricName": "Errors",
               "namespace": "AWS/Lambda",
               "period": "$period",
               "refId": "A",