function resolveUnitlessLineHeight(style: ReactNativeStyle): ReactNativeStyle {
  if (typeof style?.lineHeight === 'string') {
    const fontSize = typeof style?.fontSize === 'number' ? style.fontSize : 16;
    style.lineHeight = parseFloat(style.lineHeight) * fontSize;
  }
  return style;
}
Unitless lineHeight acts as a fontSize multiplier. It is only fully resolved
at the point at which an element is being styled, so that inherited values
remain correct rather than being prematurely resolved to pixel values.
Note: this mutates the input.