Update mkbootimg to the latest version of AOSP

[FlorentRevest]

Starting from the following commit, made 6 months ago, Google has turn mkbootimg into a python script https://android.googlesource.com/platform/system/core/+/ad6ec0c7fe8b5cd80dff619f1d3b6067db85110a

My pull request update the binary mkbootimg file of this repo with the latest python script from Google.

I tested mkboot with this script and there is no regression from the previous mkbootimg this repository used to provide.

This also close issue #16 which is really important for my AsteroidOS project:

• Firstly it ensures the components are fully open-source and we know how they work
• Secondly, it fixes an error reported by several users with the prebuilt version of mkbootimg: /usr/bin/mkbootimg: error while loading shared libraries: libstdc++.so.6: cannot open shared object file: No such file or directory

[ghost]

Not only that, but mkbootimg.c and its needed headers are also open source as well. GCC is typically standard on any Linux distro so maybe providing its source and having the mkboot script compile it on each machine during runtime would be more proficient and thus eliminate any shared object issues amongst the different users.