WazzapMigrator Extractor has been designed to make extraction from iTunes backup a one-click process, totally free and easy to perform. It will automatically extract the files required for the migration, both ChatStorage.sqlite and all your media. 

After the extraction, you just need to move everything to the Download folder of your Android phone and run WazzapMigrator. If you want to go wire-free, you can let it upload automatically on Google Drive, just accept as in the screenshot below. 

 If you copy the media folder manually to your phone, make sure to compress it to zip archive before copying by using the option "Compress media folder".