[TIMOB-10563] MobileWeb: Double tapping on any tab makes the back button to disappear for that tab

This is not a regression,issue is seen on 2.1.1 GA. Steps to reproduce: 1.Package the kitchensink app for mobileweb. 2.Host it on to your apache server. 3.Fireup the app in device browser. 4.Now tap on any tab e.g phone. 5.Tap on e.g shake table row in phone tab. 6.Now again tap on the phone tab.this takes us back to the table rows in the phone tab. 7.Now tap on any table row e.g contacts in the phone tab. 8.You will see that after the test in the contacts is launched & when you go to tap on the back button the back button disappears. Note : This only happens in the same tab.The back button will not disappear for a table row in any other tab. Actual result: 1.Double tapping on any tab makes the back button to disappear for that tab. Expected result: 2.The back button should not disappear.