[CI] Metricbeat: set AWS region to terraform.tf (#39675) (#39701)

* [CI] Metricbeat: set AWS region to terraform.tf

* Cleanup

* Fix DB instance type

(cherry picked from commit 44679fb)

Co-authored-by: Pavel Zorin <pavel.zorin@elastic.co>

.buildkite/x-pack/pipeline.xpack.metricbeat.yml

@@ -187,8 +187,6 @@ steps:
 
       - label: ":linux: Cloud (MODULE) Tests"
         key: "x-pack-metricbeat-extended-cloud-test"
-        skip: "Not a stage on Jenkins & elastic/ingest-dev#3170"
-        # https://github.com/elastic/ingest-dev/issues/3170
         if: build.env("GITHUB_PR_LABELS") =~ /.*aws.*/
         command: |
           set -euo pipefail

x-pack/metricbeat/module/aws/terraform.tf

@@ -1,5 +1,6 @@
 provider "aws" {
   version = "~> 3.33"
+  region = "us-east-1"
   default_tags {
     tags = {
       environment  = var.ENVIRONMENT
@@ -32,7 +33,7 @@ resource "aws_db_instance" "test" {
   identifier          = "metricbeat-test-${random_id.suffix.hex}"
   allocated_storage   = 20 // Gigabytes
   engine              = "mysql"
-  instance_class      = "db.t2.micro"
+  instance_class      = "db.t3.micro"
   name                = "metricbeattest"
   username            = "foo"
   password            = random_password.db.result