TIMOB-17016-Since Android restore fragments on orientation change, make ...

Added empty constructor so that Android can restore the state. Since Android restore fragments on orientation change, make sure the properties are set correctly

https://jira.appcelerator.org/browse/TIMOB-17016
I had tried this but the activity that is returned from the TabGroupProxy is the main application activity and not the window activity. The window activity is stored in the variable tabGroupActivity and is exposed through getWindowActivity but it is protected method.