terraform/: add new region us-east1

Change-Id: I5220a50ad7efd0769ee2cfa4765ca585b5efd80b
Reviewed-on: https://go-review.googlesource.com/c/pkgsite-metrics/+/705275
Reviewed-by: Ethan Lee <ethanalee@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

terraform/main.tf

diff --git a/terraform/main.tf b/terraform/main.tf
index e835112..b742a46 100644
--- a/terraform/main.tf
+++ b/terraform/main.tf
@@ -285,7 +285,7 @@
   source                = "./environment"
   env                   = "prod"
   project               = var.prod_project
-  regions                = [local.region]
+  regions                = ["us-central1", "us-east1"]
   pkgsite_db_project    = var.pkgsite_db_project
   pkgsite_db_name       = var.pkgsite_db_name
   vulndb_bucket_project = var.vulndb_bucket_project