<!--- 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

```

from __future__ import absolute_import, division, print_function
__metaclass__ = type
ANSIBLE_METADATA = {'metadata_version': '1.1',
                    'status': ['preview'],
                    'supported_by': 'community'}
DOCUMENTATION = r'''
---
module: vmware_export_ovf
short_description: Exports a VMware virtual machine to an OVF file, device files and a manifest file
description: >
   This module can be used to export a VMware virtual machine to OVF template from vCenter server or ESXi host.
version_added: '2.8'
author:
- Diane Wang (@Tomorrow9) <dianew@vmware.com>
requirements:
- python >= 2.6
- PyVmomi
notes: []
options:
  name:
    description: