Fix bbl up for AWS
Fix bbl up for AWS

- Different calls to AWS return different lists of availability zones
- Short-term fix ignores the az that is not returned by cloudformation
  call

  [#139857703]

niroyb/bosh-bootloader,pivotal-cf-experimental/bosh-bootloader,pivotal-cf-experimental/bosh-bootloader,niroyb/bosh-bootloader