In the LAMW demo folder;Code: Pascal [Select][+][-]..............\lazandroidmodulewizard-master\demos\GUI\appLamwUnzipDemo
How to do 7z and rar?
I have no idea as I don't work with these formats.But ; Something useful can be done by making use of the https://forum.lazarus.freepascal.org/index.php?topic=46180.0 and https://www.freepascal.org/~michael/articles/archives/archives.pdf links.
APK itself compressed ,Probably no need of compression .But window or Linux file Manager provide all these utility.