<!--- Verify first that your issue is not already reported on GitHub -->
<!--- Also test if the latest release and devel branch are affected too -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### SUMMARY
<!--- Explain the problem briefly below -->
If target VM has big disk file, exporting to ovf will timeout in 10 minutes. 
"timeout" can be set as a module parameter to let user set the timeout value for different scenarios.
##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
vmware_export_ovf
##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
ansible 2.8.1
  config file = /root/ansible.cfg
  configured module search path = [u'/root/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python2.7/dist-packages/ansible
  executable location = /usr/bin/ansible
  python version = 2.7.15rc1 (default, Nov 12 2018, 14:31:15) [GCC 7.3.0]
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below

```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->


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

<!--- Paste example playbooks or commands between quotes below -->
```yaml

```

<!--- HINT: You can paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
VM can be exported.

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->
Timeout occurred.
<!--- Paste verbatim command output between quotes -->
```paste below

```

self.progressPercent = progress_percent
    def stop(self):
        self._running = False
    def run(self):
        while self._running:
            try:
                if self.httpNfcLease.state == vim.HttpNfcLease.State.done:
                    return
                self.httpNfcLease.HttpNfcLeaseProgress(self.progressPercent)
                sleep_sec = 0
                while True:
                    if self.httpNfcLease.state == vim.HttpNfcLease.State.done or self.httpNfcLease.state == vim.HttpNfcLease.State.error:
                        return
                    sleep_sec += 1
                    sleep(1)
                    if sleep_sec == self.updateInterval:
                        break
            except Exception:
                return
class VMwareExportVmOvf(PyVmomi):
    def __init__(self, module):
        super(VMwareExportVmOvf, self).__init__(module)
        self.mf_file = ''
        self.ovf_dir = ''
        
        self.chunk_size = 2 * 2 ** 20
        
        self.lease_interval = 15
        self.facts = {'device_files': []}
    def create_export_dir(self, vm_obj):