when the cyberfront's servers were still available, once you brought the voice DLC, the game would download and unpack everything from a file named VOICE.PCK to /sdcard/Android/obb/cyberfront.online.Ever17/17AHXLeMMIHAHX34/AHX/
the game writes a file called "DLCDATA" to the app's internal data directory (not to be confused with /sdcard/Android/data) with the "complete" flag and a comma when the DLC download is "complite"
- complete = 3
- failed = 2
- uninstalled? = 4