Dragon Ball Z: Kakarot is out but there is an issue. It is not possible to change gamepad controls in the game settings. You can configure your controller buttons in Steam Big Picture Mode.
- While in the game, go to the Steam Big Picture Mode, at the top-right corner of the screen.
- Click on the Settings icon
- Go to the Controller Settings
- Tick your controller in the list.
- After that, select your gamepad under the "Detected Controllers" section.
- Now, hit the "Define Layout"
- You can edit the controls as you wish on the page that opens.