error: duplicate value for resource 'attr/tint' with config ''

In my project. I should delete
 `format="string"` 
in 
```
<declare-styleable name="NestedRadioGroup">
        <attr name="checkedButton" format="reference"/>
        <attr name="orientation"/>
    </declare-styleable>
```

don't know why.
Maybe because the format of 'oratation' has already been defined before in sdk.
Wish this info can help you fix it.