There are platform-specific differences in the RadioButton appearance
that's why iOS version has only the tick icon. The main RadioButton is
adjusting the appearance based on the device system.
If you would like to have RadioButton following platform guidelines for
Android you can use RadioButton.Android:
<View>
<RadioButton.Android
value="first"
status={ checked === 'first' ? 'checked' : 'unchecked' }
onPress={() => setChecked('first')}
/>
<RadioButton.Android
value="second"
status={ checked === 'second' ? 'checked' : 'unchecked' }
onPress={() => setChecked('second')}
/>
</View>