Open GTA: San Andreas. Start a (saved games from the vanilla version will crash). You should spawn inside a police locker room wearing an LSPD uniform. If you see a black screen, you missed the CLEO installation.

Downloading mods for GTA San Andreas on Android often involves using or AML-based libraries that allow you to take on the role of a police officer, complete with uniforms and missions. Popular Police Mods for Android