Fix new new module_style determination. Fixes #5148

The `ansible.module_common._find_snippet_imports` method improperly detects the "new new" module_style as `old` because it is looking for `ansible.snippets` instead of `ansible.module_utils`

This causes `--check` mode to fail with:

```
demo | success >> {
    "msg": "cannot yet run check mode against old-style modules",
    "skippped": true
}
```