Update file efs.tf

Added backups to EFS terraform build

terraform/efs.tf

@@ -11,4 +11,7 @@ resource "aws_efs_mount_target" "secure-agent-fs-mount" {
   subnet_id      = sort(data.aws_subnets.subnets.ids)[0]
   security_groups = [
   data.aws_security_group.sec-group.id]
+  backup_policy {
+    status = "ENABLED"
+  }
 }