[FR]: Misused of DisposableEffect instead of LaunchedEffect

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Describe the problem

in MainActivity to update the dark content of the system bars to match the theme, there is a DisposableEffect which `onDispose` method is empty with no comment

```
DisposableEffect(systemUiController, darkTheme) {
systemUiController.systemBarsDarkContentEnabled = !darkTheme
onDispose {}
}
```

this code exists in MainActivity:103

### Describe the solution

I can update it and use LaunchedEffect instead

### Additional context

_No response_

### Code of Conduct

- [X] I agree to follow this project's Code of Conduct

Start in MainActivity around line 103 and inspect the effect that updates the system bar dark-content setting for the theme. Replace the empty-disposal effect as described, then verify that the system bars still match the current theme; no test file is mentioned in the issue.

Written by the indexing model from the issue text.