##### SUMMARY
If you have executable files in your source code they are not kept in the tarball.

Could be related to https://github.com/ansible/ansible/blob/99d7f150873011e7515851db9b44ff486efa9d77/lib/ansible/galaxy/collection.py#L763

This was noticed as I had some auxiliary scripts in my repo.

Need to also consider scripts in `files/` if/when Collections support roles.

This seems to fail the "principal of least suprise"

**Proposal 1: Keep on stripping executable flags**

Add some line to the output
`WARNING: tests/coverage.sh: source file has executable flag, though this will be ignored in generated tar.gz`
Update developing a collection documentation page
Update integration tests to ensure that executable mode is always stripped.
Update code to link to this issue

**Proposal 2: Allow executible flags**

Update developing a collection documentation page
Update integration tests to ensure that executable mode is preserved
Update code to link to this issue
Changelog


##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
ansible-galaxy

##### ANSIBLE VERSION
```paste below
2.10
```

##### 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 -->


with _tarfile_extract(collection_tar, member) as member_obj:
                    try:
                        info[property_name] = json.loads(to_text(member_obj.read(), errors='surrogate_or_strict'))
                    except ValueError:
                        raise AnsibleError("Collection tar file member %s does not contain a valid json string."
                                           % n_member_name)
        meta = info['manifest_file']['collection_info']
        files = info['files_file']['files']
        namespace = meta['namespace']
        name = meta['name']
        version = meta['version']
        meta = CollectionVersionMetadata(namespace, name, version, None, None, meta['dependencies'])
        if SemanticVersion(version).is_prerelease:
            allow_pre_release = True
        else:
            allow_pre_release = False
        return CollectionRequirement(namespace, name, b_path, None, [version], version, force, parent=parent,
                                     metadata=meta, files=files, allow_pre_releases=allow_pre_release)
    @staticmethod
    def from_path(b_path, force, parent=None):
        info = {}
        for b_file_name, property_name in CollectionRequirement._FILE_MAPPING:
            b_file_path = os.path.join(b_path, b_file_name)
            if not os.path.exists(b_file_path):
                continue
            with open(b_file_path, 'rb') as file_obj:
                try:
                    info[property_name] = json.loads(to_text(file_obj.read(), errors='surrogate_or_strict'))
                except ValueError:
                    raise AnsibleError("Collection file at '%s' does not contain a valid json string."