Iterate through requested access approving or not.

def ApprovalGrant(token=None):
  """Iterate through requested access approving or not."""
  user = getpass.getuser()
  notifications = GetNotifications(user=user, token=token)
  requests = [n for n in notifications if n.type == "GrantAccess"]
  for request in requests:
    _, client_id, user, reason = rdfvalue.RDFURN(request.subject).Split()
    reason = utils.DecodeReasonString(reason)
    print(request)
    print("Reason: %s" % reason)
    if input("Do you approve this request? [y/N] ").lower() == "y":
      security.ClientApprovalGrantor(
          subject_urn=client_id, reason=reason, delegate=user,
          token=token).Grant()
      # TODO(user): Remove the notification.
    else:
      print("skipping request")
    print("Approval sent")