feat!: improved android picker + remove variants

[henninghall]

Breaking

• Removed androidVariant prop. From now on only nativeAndroid variant is supported, iosClone is removed.
• Removed fadeToColor prop. No need for this since iosClone variant is no longer supported.
• Removed dividerHeight prop. No need for this since iosClone variant is no longer supported.
• Removed textColor prop. Use theme prop to make text dark or light if defaults aren't good enough. Remove because of inconsistent iOS support.

Features

• Added buttonColor prop. Easier to use than the previously suggested method of changing Android xml config.
• Added dividerColor prop. Easier to use than the previously suggested method of changing Android xml config.

Improvements

• Increased fling velocity of the previously called nativeAndroid picker. It roughly matches the previously called iosClone's fling velocity.
• Internally exposed an improved version of the core android NumberPicker component. Patched from Android source code. Enables more internal modifications of the core component than previously possible.
• Removed dependency of maven and NumberPickerView android component.