False positive Magento2.Legacy.ObsoleteResponse

### Preconditions

1. a class that uses **property** (not method) `_redirect` or `loadLayout`
2. magento-coding-standard v16

### Steps to reproduce

1. a class that uses **properties** (not methods) that are listed in the list of [methods](https://github.com/magento/magento-coding-standard/blob/v16/Magento2/Sniffs/Legacy/ObsoleteResponseSniff.php#L18-L29)
```
renderLayout === null) {
$a = 1;
}
if ($this->_redirect === null) {
$b = 2;
}
}
}

```
2. run `phpcs`

### Expected result

1. No `Magento2.Legacy.ObsoleteResponse` triggered

### Actual result

```
FILE: /Model/MyModel.php
-----------------------------------------------------------------------------------------------------------------------------------
FOUND 0 ERRORS AND 2 WARNINGS AFFECTING 2 LINES
-----------------------------------------------------------------------------------------------------------------------------------
24 | WARNING | renderLayout method is deprecated. Please use \Magento\Framework\Controller\ResultInterface::renderResult instead.
27 | WARNING | _redirect method is deprecated. Please use \Magento\Backend\Model\View\Result\Redirect::render instead.
-----------------------------------------------------------------------------------------------------------------------------------
```

Start with Magento2/Sniffs/Legacy/ObsoleteResponseSniff.php, especially the methods list linked in the issue, and reproduce the report by running phpcs on the example class. Done means properties named renderLayout or _redirect no longer trigger Magento2.Legacy.ObsoleteResponse, while the issue's expected output remains satisfied.

Written by the indexing model from the issue text.