<!--- Verify first that your feature was not already discussed on GitHub -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### SUMMARY
<!--- Describe the new feature/improvement briefly below -->
Use case is for customers on air-gapped customers who want to take the tarball using a flash drive inside their network.
Currently that is not possible because cli does not keep the tarball after installing the collection.

##### ISSUE TYPE
- Feature Idea

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

##### ADDITIONAL INFORMATION
<!--- Describe how the feature would be used, why it is needed and what it would solve -->

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

```

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

if missing_keys:
        raise AnsibleError("The collection galaxy.yml at '%s' is missing the following mandatory keys: %s"
                           % (to_native(b_galaxy_yml_path), ", ".join(sorted(missing_keys))))
    extra_keys = set_keys.difference(all_keys)
    if len(extra_keys) > 0:
        display.warning("Found unknown keys in collection galaxy.yml at '%s': %s"
                        % (to_text(b_galaxy_yml_path), ", ".join(extra_keys)))
    
    for optional_string in string_keys:
        if optional_string not in galaxy_yml:
            galaxy_yml[optional_string] = None
    for optional_list in list_keys:
        list_val = galaxy_yml.get(optional_list, None)
        if list_val is None:
            galaxy_yml[optional_list] = []
        elif not isinstance(list_val, list):
            galaxy_yml[optional_list] = [list_val]
    for optional_dict in dict_keys:
        if optional_dict not in galaxy_yml:
            galaxy_yml[optional_dict] = {}
    
    galaxy_yml['license_ids'] = galaxy_yml['license']
    del galaxy_yml['license']
    return galaxy_yml
def _build_files_manifest(b_collection_path, namespace, name, ignore_patterns):
    
    
    b_ignore_patterns = [
        b'galaxy.yml',
        b'*.pyc',