doc: fix full integration example

Author: Qingping Hou

examples/full_integration/main.tf

@@ -22,12 +22,13 @@ provider "aws" {
   region = var.aws_region
 }
 
+data "aws_caller_identity" "current" {}
+
 module "datadog" {
   source          = "scribd/datadog/aws"
   version         = "~>1"
   aws_region      = var.aws_region
   datadog_api_key = var.dd_api_key
-  datadog_app_key = var.dd_app_key
   aws_account_id  = data.aws_caller_identity.current.account_id
 
   cloudtrail_bucket_id  = "S3_BUCKET_ID"