[TIMOB-14608]  3_1_X IOS: Supporting new icons for icons

Backport of #4500

Introducing two new icons appicon-60 &60@2x , appicon-Small-40.png &40@2x.png

__Testing Instruction__

* According to apple in iOS 7 all we have to do include all the icons needed in the build project and include them in the CFBundleIconFiles inside info.plist

steps.
* Import this [project](https://dl.dropboxusercontent.com/u/43336767/icontest.zip) into studio
* Build for device.
* find the build .ipa ,rename it to .zip and open it up.
* Check to verify that all the icons are inside the build folder
* Check to verify that all the icons inside the build folder are mentioned inside the <CFBundleIconFiles> inside info.plist