main.8.com.rockstargames.gtasa.obb
The file is a primary expansion file for the Android version of Grand Theft Auto: San Andreas
Some legitimate Android backup utilities (like Swift Backup or Helium) allow you to back up APK + OBB combos. If you previously backed up your game, restore from there.
Verification
Move this file into the folder mentioned above. If the com.rockstargames.gtasa folder does not exist, you must create it manually. :
What is an OBB File?
Part 2: The Legal Landscape – A Critical Warning
The main.8 OBB file for GTA: San Andreas typically contains the game's internal directory structure. Once extracted or mounted by the operating system, it usually contains folders such as: