add cloudwatch:PutMetricData permission

Author: Vlasis-Perdikidis

infrastructure/terraform/components/api/module_lambda_upsert_letter.tf

@@ -85,4 +85,16 @@ data "aws_iam_policy_document" "upsert_letter_lambda" {
       module.sqs_letter_updates.sqs_queue_arn
     ]
   }
+
+  statement {
+    sid = "AllowCloudWatchMetrics"
+    effect = "Allow"
+
+    actions = [
+      "cloudwatch:PutMetricData"
+    ]
+
+    resources = ["*"]
+  }
+
 }