api of pie chart (entryLabelColor, entryLabelTextSize) does not match MpAndroidChart

Hi

I am working on a react native chart wrapper base on MpAndroid and Charts, [link](https://github.com/wuxudong/react-native-charts-wrapper)

I found that there are following attributes in MpAndroidChart pie chart

`pieChart.setEntryLabelColor(color)`
`pieChart.setEntryLabelTextSize(size)`

In Charts, there are also entryLabelColor & entryLabelFont in pie chart, but they won't work.

In PieChartRender.swift, it use dataSet.entryLabelColor, dataSet.entryLabelFont instead.

let entryLabelColor = chart.entryLabelColor
let entryLabelFont = chart.entryLabelFont

.....

for i in 0 ..< dataSets.count
{

......

let entryLabelFont = dataSet.entryLabelFont

.......
}

but in MpAndroid, pieDataSet doesn't have such attributes.