Samsung has recently provided the official Android 4.1.2 Jelly Bean update with build version XWLSE for the international version of Galaxy S2 (model number-I9100) users from Russia. The XWLSE Jelly Bean is a completely unbranded version of the firmware and can be installed via Samsung Kies. This firmware reportedly addresses bug issues found in the previous build and brings some enhancements. Since it an unbranded version of firmware, it can be installed even by those who are not from Russia. The only condition is that your phone should not be a carrier locked Galaxy S2 and you can update to the latest version of JellyBean.
How to Update/Install Galaxy S2 to Android JellyBean 4.1.2 Official Firmware [Tutorial]
