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##### SUMMARY
The XML got by executing the following playbook was a byte string.

##### playbook

```yaml
---
- name: Get template from zabbix server
  hosts: localhost
  gather_facts: no
  tasks:
    - zabbix_template:
        server_url: "{{ zabbix_server }}"
        login_user: "{{ zabbix_user }}"
        login_password: "{{ zabbix_password }}"
        template_name: Template App Zabbix Proxy
        dump_format: xml
        state: dump
      register: template_xml

    - debug: var=template_xml
```

##### run playbook

```
$ ansible-playbook main.yml
 [WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'


PLAY [Get template from zabbix server] *****************************************************************************************************************************************

TASK [zabbix_template] *********************************************************************************************************************************************************
ok: [localhost]

TASK [debug] *******************************************************************************************************************************************************************
ok: [localhost] => {
    "template_xml": {
        "changed": false,
        "failed": false,
        "template_xml": "b'<zabbix_export><version>3.0</version><date>....</graphs></zabbix_export>'"
```

In RETURN, the return value is a string.
https://github.com/ansible/ansible/blob/358574d57f2b411e820cbf4d00a8249ac8291cb9/lib/ansible/modules/monitoring/zabbix/zabbix_template.py#L259

So, I think the return value should be a string.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
zabbix_template

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
$ ansible --version
ansible 2.8.5
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/root/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /root/dev/venv/lib64/python3.6/site-packages/ansible
  executable location = /root/dev/venv/bin/ansible
  python version = 3.6.8 (default, Aug  7 2019, 17:28:10) [GCC 4.8.5 20150623 (Red Hat 4.8.5-39)]
```

```
$ pip3 show zabbix-api
Name: zabbix-api
Version: 0.5.4
Summary: Zabbix API
Home-page: https://github.com/gescheit/scripts
Author: Aleksandr Balezin
Author-email: gescheit12@gmail.com
License: GNU LGPL 2.1
Location: /root/dev/venv/lib/python3.6/site-packages
```

```
$ python --version
Python 3.6.8
```

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

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

```
$ cat /etc/redhat-release
CentOS Linux release 7.6.1810 (Core)
```
"""Filters out keys from XML template that may wary between exports (e.g date or version) and
        keys that are not imported via this module.
        It is advised that provided XML template exactly matches XML structure used by Zabbix"""
        
        parsed_xml_root = self.load_xml_template(template_xml.strip())
        keep_keys = ['graphs', 'templates', 'triggers', 'value_maps']
        
        for node in list(parsed_xml_root):
            if node.tag not in keep_keys:
                parsed_xml_root.remove(node)
        
        for template in list(parsed_xml_root.find('templates')):
            for element in list(template):
                if element.text is None and len(list(element)) == 0:
                    template.remove(element)
        
        xml_root_text = list(line.strip() for line in ET.tostring(parsed_xml_root).split('\n'))
        return ''.join(xml_root_text)
    def load_json_template(self, template_json):
        try:
            return json.loads(template_json)
        except ValueError as e:
            self._module.fail_json(msg='Invalid JSON provided', details=to_native(e), exception=traceback.format_exc())
    def load_xml_template(self, template_xml):
        try:
            return ET.fromstring(template_xml)
        except ET.ParseError as e:
            self._module.fail_json(msg='Invalid XML provided', details=to_native(e), exception=traceback.format_exc())
    def import_template(self, template_content, template_type='json'):