Partly offtopic --> upgrading android OS

btw. it's Huawei S7 lite

Maybe, but it's tricky. If there's no vendor-supplied upgrade you'd may have to "roll your own".

There are some sites out there which have software-install images for various older devices, typically based on a combination of AOSP (the Android open-source version) and the hardware-specific board-support files (usually extracted from one of the vendor's officially-supported release images, or extracted from the device itself). There are also some procedures out there that you can use to build your own install image of this sort, by building AOSP and merging in the board-support files.

The most popular third-party install images are probably the "CyanogenMod" kits. Unfortunately the S7 Lite isn't on the official-ports list, and the "unofficial" Android 4.2.2 port for the S7-30Xx says "not for Lite or 10HD".

In order to install any unofficial upgrade, you must usually unlock the boot-loader (so you can install an image not officially signed by the manufacturer)... and unlocking the bootloader _will_ wipe the device's data storage clean, as a security measure.

Unless you can find an image from somebody who has already worked out an upgrade for your specific device, you're in for a substantial amount of work, and a very real risk that you'll accidentally "brick" the device by installing a bad or incomplete image. I believe it's _usually_ possible to re-flash a factory image and recover from this, but if you really manage to clobber the bootloader you'll end up with a very thin brick which is suitable only for sending off to recycling.

Also, be aware that many older devices simply don't have enough RAM, flash storage, and/or CPU power to run the more recent Android versions effectively. "Upgrading" might end up being a downgrade in usability.

OK. Thank you for great answer !