Cisco object-group ACLs don't properly render ICMP type and code

Policy terms with an icmp type and code are not correctly rendered when using the `Cisco` generator and the `object-group` argument. The rendered lines are missing the icmp-type and code.

For example, using the following policy:
```
# NETWORK.net
header {
target:: ciscoxr ICMP_EXAMPLE object-group
}

term PERMIT_ICMP_ECHO_REPLY {
protocol:: icmp
action:: accept
icmp-type:: echo-reply
}
```

`aclgen` renders the following:

```
! $Id:$
! $Date:$
! $Revision:$
no ip access-list extended ICMP_EXAMPLE
ip access-list extended ICMP_EXAMPLE
remark $Id:$

remark PERMIT_ICMP_ECHO_REPLY
permit icmp any any

exit
```

Note the missing icmp-type following `permit icmp any any`. The expected output is:
```
! $Id:$
! $Date:$
! $Revision:$
no ip access-list extended ICMP_EXAMPLE
ip access-list extended ICMP_EXAMPLE
remark $Id:$

remark PERMIT_ICMP_ECHO_REPLY
permit icmp any any 0

exit
```