React Native Picker Select: How to auto-select an item but still be able to select others?

I'm using RNPickerSelect in my React Native app. I want to have three options: A B and C. I want A to be selected by default (like how USA is often selected by default in a picker list of countries). Here's what I tried:

<RNPickerSelect
  value={{label: 'A', value: 'A'}}
    items={[
      { label: 'A', value: 'A' },
      { label: 'B', value: 'B' },
      { label: 'C', value: 'C' },
    ]}
  onValueChange={value => {}}
/>

This does select A by default, but the problem is that it then doesn't allow you to select any other the others after.

How should I approach this?

First make a component state like

class DropDown extends Component {
   constructor() {
      this.state = {
          dropdownValue: 'A'
      }
   }
   
   handleDropdownChange = (name) => (value) => {
      this.setState({ [name]: value })
   }
   
   render() {
      const { dropdownValue } = this.state  

      return (
         <RNPickerSelect
            value={dropdownValue}
            items={[
              { label: 'A', value: 'A' },
              { label: 'B', value: 'B' },
              { label: 'C', value: 'C' },
            ]}
            onValueChange={this.handleDropdownChange('dropdownValue')}
         />
      )
   }
}