If you want to lock your stats to those values permanently, you'll need to use the cwcheat database (I don't know how that works on Android, but there's a straightforward menu for it in Windows PPSSPP). If you just want the max values at their limits and be able to have enemies hit you, you can buff yourself with Lion Editor, provided you disable save data encryption within PPSSPP (which, again, I have no idea how to do on Android).
I don't think there are job-altering cheats in the database (as it wasn't nearly as extensively documented as the PlayStation original everybody who wants to mod the game should be playing), so you'll have to change the abilities by altering the ISO itself in FFTPatcher. It's very simple and straightforward to use, no tutorial needed.
