##### SUMMARY
get_vm() method vmware.py module utility fails with KeyError if uuid is not in the module param from whch method is invoked

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
vmware.py module util

##### ANSIBLE VERSION
```
ansible 2.9.0.dev0
```

##### OS / ENVIRONMENT
Ubuntu 16

##### STEPS TO REPRODUCE
Creating new module. 'uuid' is not in my module arguments. 
Called get_vm() 

pyv = PyVmomi(module=module)
vm = pyv.get_vm()

##### EXPECTED RESULTS
Call should return vm_id if it exists

##### ACTUAL RESULTS
```
Get error
An exception occurred during task execution. To see the full traceback, use -vvv. The error was: KeyError: 'uuid'
fatal: [localhost]: FAILED! => {"changed": false, "module_stderr": "Traceback (most recent call last):\n  File
\"/home/vmware/.ansible/tmp/ansible-tmp-1565095783.75439-259726275713856/AnsiballZ_vmware_content_deploy_template.py\", line 125, in <module>\n    _ansiballz_main()\n  File \"/home/vmware/.ansible/tmp/ansible-tmp-1565095783.75439-259726275713856/AnsiballZ_vmware_content_deploy_template.py\", line 117, in _ansiballz_main\n    invoke_module(zipped_mod, temp_path, ANSIBALLZ_PARAMS)\n  File \"/home/vmware/.ansible/tmp/ansible-tmp-1565095783.75439-259726275713856/AnsiballZ_vmware_content_deploy_template.py\", line 51, in invoke_module\n    spec.loader.exec_module(module)\n  File \"<frozen importlib._bootstrap_external>\", line 665, in exec_module\n  File \"<frozen importlib._bootstrap>\", line 222, in _call_with_frames_removed\n  File \"/tmp/ansible_vmware_content_deploy_template_payload_69cftg21/__main__.py\", line 271, in <module>\n  File \"/tmp/ansible_vmware_content_deploy_template_payload_69cftg21/__main__.py\", line 241, in main\n  File \"/tmp/ansible_vmware_content_deploy_template_payload_69cftg21/ansible_vmware_content_deploy_template_payload.zip/ansible/module_utils/vmware.py\", line 891,
in get_vm\nKeyError: 'uuid'\n", "module_stdout": "", "msg": "MODULE FAILURE\nSee stdout/stderr for the exact error", "rc": 1}

```

port_key = entry.backing.port.portKey
        else:
            port_group_key = None
            port_key = None
        factname = 'hw_eth' + str(ethernet_idx)
        facts[factname] = {
            'addresstype': entry.addressType,
            'label': entry.deviceInfo.label,
            'macaddress': mac_addr,
            'ipaddresses': net_dict.get(entry.macAddress, None),
            'macaddress_dash': mac_addr_dash,
            'summary': entry.deviceInfo.summary,
            'portgroup_portkey': port_key,
            'portgroup_key': port_group_key,
        }
        facts['hw_interfaces'].append('eth' + str(ethernet_idx))
        ethernet_idx += 1
    snapshot_facts = list_snapshots(vm)
    if 'snapshots' in snapshot_facts:
        facts['snapshots'] = snapshot_facts['snapshots']
        facts['current_snapshot'] = snapshot_facts['current_snapshot']
    facts['vnc'] = get_vnc_extraconfig(vm)
    return facts
def deserialize_snapshot_obj(obj):
    return {'id': obj.id,
            'name': obj.name,
            'description': obj.description,
            'creation_time': obj.createTime,
            'state': obj.state}
def list_snapshots_recursively(snapshots):