[allwpilib codex] Update GamepadChooserTest to camel_case

### Problem description

https://github.com/wpilibsuite/allwpilib/pull/9041#pullrequestreview-4667957779

```
With the wpilib bindings now generated as snake_case and enum values as CAPS_CASE, this example still calls setMode, Mode.Line, addOptions, and the other camelCase chooser/display methods in both autonomous constructors. Running the DSGamepadChooser example now raises AttributeError before the opmodes can be used; update these calls to the same names used by the converted tests (set_mode, Mode.LINE, add_options, etc.).
```

### Operating System

Linux

### Installed Python Packages

```text

```

### Reproducible example code

```text

```

Open GamepadChooserTest and the DSGamepadChooser example, then compare their chooser and display calls with the converted tests referenced in the issue. Update the remaining camelCase method calls and enum values in both autonomous constructors, and confirm the example no longer raises AttributeError when run.

Written by the indexing model from the issue text.