[TIMOB-28425] Android: Change "plain" Ti.UI.Picker to use native spinners

*Summary:* When a Ti.UI.Picker of type PICKER_TYPE_PLAIN is set up with "useSpinner" set to true, it uses a custom spinner which looks just like the old iOS spinner widget. It should use Android's native Java [NumberPicker](https://developer.android.com/reference/android/widget/NumberPicker) view which would support colors defined in theme, support dark/light theme switching, and correclty DPI scale. *Test:* Build and run [^SpinnerSimpleTest.js] on Android. *Current Result:* Displays a custom picker that looks like the old iOS spinner widget. Does not support colors defined by Android theme. Does not support dark/light theme. !Spinner-Light-Old.png|thumbnail! !Spinner-Dark-Old.png|thumbnail! *Expected Result:* We should change it to use native Android spinners which appear as... !Spinner-Light-New.png|thumbnail! !Spinner-Dark-New.png|thumbnail! *Note:* Once we replace it with the native NumberPicker Java view, we can remove the custom "kankan" spinner Java classes from our SDK here... https://github.com/appcelerator/titanium_mobile/tree/master/android/modules/ui/src/java/kankan/wheel/widget