##### 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}

```

pass
    if vm.summary.runtime.dasVmProtection:
        facts['hw_guest_ha_state'] = vm.summary.runtime.dasVmProtection.dasProtected
    datastores = vm.datastore
    for ds in datastores:
        facts['hw_datastores'].append(ds.info.name)
    try:
        files = vm.config.files
        layout = vm.layout
        if files:
            facts['hw_files'] = [files.vmPathName]
            for item in layout.snapshot:
                for snap in item.snapshotFile:
                    if 'vmsn' in snap:
                        facts['hw_files'].append(snap)
            for item in layout.configFile:
                facts['hw_files'].append(os.path.join(os.path.dirname(files.vmPathName), item))
            for item in vm.layout.logFile:
                facts['hw_files'].append(os.path.join(files.logDirectory, item))
            for item in vm.layout.disk:
                for disk in item.diskFile:
                    facts['hw_files'].append(disk)
    except Exception:
        pass
    facts['hw_folder'] = PyVmomi.get_vm_path(content, vm)
    cfm = content.customFieldsManager
    
    for value_obj in vm.summary.customValue: