Revert machine type change

Author: gururajsh

.github/ops-files/bosh-lite-vm-type.yml

@@ -2,7 +2,7 @@
 # Configure sizes for bosh-lite on gcp
 - type: replace
   path: /resource_pools/name=vms/cloud_properties/machine_type
-  value: n2-standard-16
+  value: n2-standard-8
 - type: replace
   path: /disk_pools/name=disks/disk_size
   value: 250000