Feature/styleprop

[tvanlaerhoven]

Replace Slider's ViewStyle props with StyleProp<ViewStyle>.

This way the style props accept not only ViewStyle types, but also a (recursive) array of ViewStyle, and a Falsy type, which translates to false || null || undefined.

A user can then pass containerStyle, minimumTrackStyle, maximumTrackStyle, thumbStyle and trackStyle as:

• array of styles: style={[styles.style1, styles.style2]}
• any Falsy value, such as style={undefined}

which is not possible with bare ViewStyle.

It makes it easier for Slider users to optionally pass style overrides in their own CustomSlider:

const StyledSlider = ({ overrideContainerStyle }: { overrideContainerStyle?: StyleProp<ViewStyle> }) => {
  return (
    <Slider containerStyle={[styles.defaultSliderContainerStyle, overrideContainerStyle]} />
  );
};

The API remains backwards compatible with previous versions.