helium-backup-extractor

Extract Helium (formely Carbon) backups.
Helium backups are normal adb backups created with boolean COMPRESS_FULL_BACKUPS = false, and the 18th byte
of the backup changed from 0 to 1 (I guess this is done by Helium intentionally).
Android should be able to restore helium backups properly, considering that first you change 18th byte from 1 to 0.
The files inside uncompressed backups don't necessarily match directly the ones in compressed format (even after decompression).