##### SUMMARY
when you gather_facts for ios_l3_interfaces 

it will gather the full subnet (e.g. 255.255.255.0 instead of /24)
```
    l3_interfaces:
    - ipv4:
      - address: 192.168.1.101 255.255.255.0
      name: loopback0
    - ipv4:
      - address: 10.1.1.101 255.255.255.0
      name: loopback1
```
but if you push this acquired data model back out, it will do this->
```
  msg: address format is <ipv4 address>/<mask>, got invalid format 10.10.10.1 255.255.255.0
```


##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
ios_l3_interfaces 

##### ANSIBLE VERSION
```paste below
ansible 2.9.0.dev0
  config file = /home/student1/.ansible.cfg
  configured module search path = [u'/home/student1/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /home/student1/.local/lib/python2.7/site-packages/ansible
  executable location = /usr/bin/ansible
  python version = 2.7.5 (default, Jun 11 2019, 14:33:56) [GCC 4.8.5 20150623 (Red Hat 4.8.5-39)]
```

##### CONFIGURATION
```paste below
DEFAULT_HOST_LIST(/home/student1/.ansible.cfg) = [u'/home/student1/networking-workshop/lab_inventory/hosts']
DEFAULT_STDOUT_CALLBACK(/home/student1/.ansible.cfg) = yaml
DEFAULT_TIMEOUT(/home/student1/.ansible.cfg) = 60
DEPRECATION_WARNINGS(/home/student1/.ansible.cfg) = False
HOST_KEY_CHECKING(/home/student1/.ansible.cfg) = False
PERSISTENT_COMMAND_TIMEOUT(/home/student1/.ansible.cfg) = 60
PERSISTENT_CONNECT_TIMEOUT(/home/student1/.ansible.cfg) = 60
RETRY_FILES_ENABLED(/home/student1/.ansible.cfg) = False
```

##### OS / ENVIRONMENT
```
NAME="Red Hat Enterprise Linux Server"
VERSION="7.6 (Maipo)"
ID="rhel"
ID_LIKE="fedora"
VARIANT="Server"
VARIANT_ID="server"
VERSION_ID="7.6"
PRETTY_NAME="Red Hat Enterprise Linux Server 7.6 (Maipo)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:7.6:GA:server"
HOME_URL="https://www.redhat.com/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"

REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 7"
REDHAT_BUGZILLA_PRODUCT_VERSION=7.6
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="7.6"
Red Hat Enterprise Linux Server release 7.6 (Maipo)
Red Hat Enterprise Linux Server release 7.6 (Maipo)
```

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml
---
- hosts: rtr1
  gather_facts: false
  tasks:
    - name: grab info
      ios_facts:
        gather_subset: min
        gather_network_resources: l3_interfaces
      register: facts_for_sean

    - name: print interface_info
      debug:
        msg: "{{ansible_network_resources}}"

    - name: print facts
      debug:
        var: facts_for_sean
```
which results in
```
    l3_interfaces:
    - ipv4:
      - address: 192.168.1.101 255.255.255.0
      name: loopback0
    - ipv4:
      - address: 10.1.1.101 255.255.255.0
      name: loopback1
    - ipv4:
      - address: 10.10.10.1 255.255.255.0
      ipv6:
      - address: fc00::100/64
      - address: fc00::101/64
      name: loopback100
    - ipv4:
      - address: dhcp
      name: GigabitEthernet1
```

now try to merge those->
```
    - ios_l3_interfaces:
        config: "{{config}}"
        state: merged
```
you will get something like
```
TASK [ios_l3_interfaces] ***********************************************************************************************
fatal: [rtr1]: FAILED! => changed=false
  msg: address format is <ipv4 address>/<mask>, got invalid format 10.10.10.1 255.255.255.0
```
##### EXPECTED RESULTS
OK pass

##### ACTUAL RESULTS
failed, does not work, wants `/24` notation 

test_dict = dict()
    test_key_dict = dict()
    name = want.get('name')
    if name:
        test_dict['name'] = name
    diff_ip = False
    want_ip = ''
    for k, v in iteritems(want):
        if isinstance(v, dict):
            for key, value in iteritems(v):