[Python APIView] Literal values in type annotations are not quoted as strings

**Bad code snippet:**
```python
type: Optional[Union[Literal[builtin], Literal[custom], Literal[all], str]] = ...
```

**Description:**
The APIView parser is incorrectly rendering Literal values in type annotations without quotes. According to Python typing guidelines, Literal values representing strings must be quoted to ensure correctness and proper type checking.

**Good code snippet:**
```python
type: Optional[Union[Literal['builtin'], Literal['custom'], Literal['all'], str]] = ...
```

Please update the parser to render string Literal values with quotes.

Start in the APIView parser and reproduce the issue with the bad Python annotation shown in the report. Compare its rendered output with the good snippet; done means string values inside Literal annotations are rendered with quotes, while the surrounding annotation remains intact.

Written by the indexing model from the issue text.