[TIMOB-15998] implemented support for attributed string on Android

https://jira.appcelerator.org/browse/TIMOB-15998

Implemented support for attributedstring
For the doc in UI Label, you could write:-
```
description: |
        If set, the label ignores the `text`, `color`, and `shadow` properties.
        For iOS, use <Titanium.UI.iOS.AttributedString>. For Android, use <Titanium.UI.AttributedString>
    type: [Titanium.UI.iOS.AttributedString, Titanium.UI.AttributedString]
```