Add aab verification script (including script for BitBanana)

This Merge Requests adds a script that allows to verify PlayStore Releases done with Android App Bundles (AAB) While the script seems to work, it has some shortcomings and in the current form is mainly done to allow verifying BitBanana.

Procedure:

1. Download file from apkcombo (https://apkcombo.com/downloader/#package=app.michaelwuensch.bitbanana&type=apks)
2. run test_aab.sh with the downloaded file
3. examine differences

Shortcomings:

• it is basically a duplicate of the test.sh script with the needed adaptions. We have duplicate code now and it might make sense to merge everything into one script. But I wanted to keep it simple for the concept. I commented a lot in the code and tried to keep it clean.
• it still uses android build box which might be overkill
• it still uses the bundletool directly, which means bundletool needs to be installed on the machine
• it does not yet detect language splits (BitBanana does not split on language, so it was not necessary for this test)

Results: I ran the script with 4 different downloads (all 4 architecture types tested + random other options). Everytime the diff --breif command resulted in 7 differences which are in my opinion ok to give the verdict "reproducible"