MaterialTimePicker使用するなら StyleがTheme.MaterialComponents.Light.NoActionBarを継承する必要ある

https://material.io/develop/android/docs/getting-started

Theme.MaterialComponents Theme.MaterialComponents.NoActionBar Theme.MaterialComponents.Light Theme.MaterialComponents.Light.NoActionBar Theme.MaterialComponents.Light.DarkActionBar Theme.MaterialComponents.DayNight Theme.MaterialComponents.DayNight.NoActionBar Theme.MaterialComponents.DayNight.DarkActionBar

res/themes.xmlで