Insert image using the width size of phone

renderImageReactNativeWithCustomSize.js

_renderImage(image) {
    let contentHeight = scaleModerate(375, 1)
    let height = Dimensions.get('window').height - contentHeight
    let width = Dimensions.get('window').width

    image = (<Image style={[style.image, {height, width}]}
                    source={ backgroundImg }/>)
    return image
}

render() {
  let image = this._renderImage()

  return (
      <RkAvoidKeyboard
          onStartShouldSetResponder={ (e) => true }
          onResponderRelease={ (e) => Keyboard.dismiss() }
          style={ style.screen }>
          { image }
  //...