[TIMOB-16900] Android: Add selected/unselected Tab events for parity with iOS Focus and Blur events

   <Alloy>
   	<TabGroup onBlur="tabGroupBlurred" onFocus="tabGroupFocused">
   		<Tab title="Tab 1" icon="KS_nav_ui.png" onBlur="tabBlurred" onFocus="tabFocused" id="tab1" onSelected="tabSelected" onUnselected="tabUnselected">
   			<Window title="Tab 1" onBlur="windowBlurred" onFocus="windowFocused">
   				<ScrollView>
   					<Label top="10dp">Switch tabs, click home button, lock screen, and watch the console events. Also make sure that keyboard dismissed when new tab selected.</Label>
   					<TextField top="120dp" width="200dp" height="Ti.UI.SIZE" backgroundColor="blue"/>
   					<Button top="180dp" title="Open Window" onClick="openWin"/>
   				</ScrollView>
   			</Window>
   		</Tab>
   		<Tab title="Tab 2" icon="KS_nav_views.png">
   			<Window title="Tab 2">
   				<Label>I am Window 2</Label>
   			</Window>
   		</Tab>
   	</TabGroup>
   </Alloy>
   

   function tabSelected(){
   	Ti.API.info('tab selected');
   }
   
   function tabUnselected(){
   	Ti.API.info('tab unselected');
   }
   
   function tabBlurred(){
   	Ti.API.info('tab blurred');
   }
   
   function tabFocused(){
   	Ti.API.info('tab focused');
   }
   
   function windowBlurred(){
   	Ti.API.info('window blurred');
   }
   
   function windowFocused(){
   	Ti.API.info('window focused');
   }
   
   function tabGroupBlurred(){
   	Ti.API.info('TabGroup blurred');
   }
   
   function tabGroupFocused(){
   	Ti.API.info('TabGroup focused');
   }
   
   function openWin() {
   	var win = Ti.UI.createWindow({backgroundColor: 'blue'});
   	$.tab1.open(win);
   }
   $.index.open();