Fix no-theme bug in Onboarding by using Radiobuttons

It was possible to de-select all Themes in the Onboarding as
Checkboxes where used. Now this is not possible anymore because we use
Radiobuttons

app/src/main/java/com/aurora/store/view/epoxy/views/ThemeView.kt

@@ -67,11 +67,11 @@ class ThemeView : RelativeLayout {
 
     @ModelProp
     fun markChecked(isChecked: Boolean) {
-        B.checkbox.isChecked = isChecked
+        B.radiobutton.isChecked = isChecked
     }
 
     @CallbackProp
     fun checked(onCheckedChangeListener: CompoundButton.OnCheckedChangeListener?) {
-        B.checkbox.setOnCheckedChangeListener(onCheckedChangeListener)
+        B.radiobutton.setOnCheckedChangeListener(onCheckedChangeListener)
     }
 }