<!--- 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 -->
When looping `include_tasks`, the loop control `loop_var` property is not defined in the included task, when the `loop_var` property has been assigned with a template.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
- loop_var
- include_tasks

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
ansible 2.8.1
  config file = /playbooks/ansible.cfg
  configured module search path = ['/root/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.7/site-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 3.7.3 (default, Jun 11 2019, 01:05:09) [GCC 6.3.0 20170516]
```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->
Redhat7
Archlinux


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

<!--- Paste example playbooks or commands between quotes below -->
```yaml
---
# main.yml
- hosts: localhost
  vars:
    loop_var_name: custom_var

  tasks:
    - include_tasks: looped-include.yml
      loop:
        - first
        - second
      loop_control:
        loop_var: "{{ loop_var_name }}"
```

```yaml
---
# looped-include.yml
- name: Print looped var
  debug:
    var: custom_var

- name: Loop default item var
  debug:
    var: item
```

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

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
We expect the variabe `custom_var` to be the looped variable, and `item` to be undefined. 

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->
Neither `custom_var` nor `item` are defined in the looped included task.

<!--- Paste verbatim command output between quotes -->
```paste below
PLAY [localhost] *****************************************************************************************

TASK [Gathering Facts] ***********************************************************************************
ok: [localhost]
included: /ansible-bug/looped-include.yml for localhost
included: /ansible-bug/looped-include.yml for localhost

TASK [Print looped var] **********************************************************************************
ok: [localhost] => 
  custom_var: VARIABLE IS NOT DEFINED!

TASK [Loop default item var] *****************************************************************************
ok: [localhost] => 
  item: VARIABLE IS NOT DEFINED!

TASK [Print looped var] **********************************************************************************
ok: [localhost] => 
  custom_var: VARIABLE IS NOT DEFINED!

TASK [Loop default item var] *****************************************************************************
ok: [localhost] => 
  item: VARIABLE IS NOT DEFINED!
```

templar = Templar(loader=loader, variables=task_vars)
                    if original_task.action in ('include', 'include_tasks'):
                        include_file = None
                        if original_task:
                            if original_task.static:
                                continue
                            if original_task._parent:
                                
                                
                                parent_include = original_task._parent
                                cumulative_path = None
                                while parent_include is not None:
                                    if not isinstance(parent_include, TaskInclude):
                                        parent_include = parent_include._parent
                                        continue
                                    if isinstance(parent_include, IncludeRole):
                                        parent_include_dir = parent_include._role_path
                                    else:
                                        try:
                                            parent_include_dir = os.path.dirname(templar.template(parent_include.args.get('_raw_params')))
                                        except AnsibleError as e:
                                            parent_include_dir = ''
                                            display.warning(
                                                'Templating the path of the parent %s failed. The path to the '
                                                'included file may not be found. '
                                                'The error was: %s.' % (original_task.action, to_text(e))
                                            )
                                    if cumulative_path is not None and not os.path.isabs(cumulative_path):
                                        cumulative_path = os.path.join(parent_include_dir, cumulative_path)
                                    else: