jaz tudi sprva nisem našel...
Go to the settings menu, and scroll down to "About phone." Tap it.
Scroll down to the bottom again, where you see "Build number." (Your build number may vary from ours here.)
Tap it seven (7) times. After the third tap, you'll see a playful dialog that says you're four taps away from being a developer. (If only it were that simple, eh?) Keep on tapping, and *poof*, you've got the developer settings
...potem se ti pa v settings čisto spodaj pojavi meni developer options.
Kar se pa razlike dalvik/ART tiče pa težko komentiram, ker mi je že prej vse delovalo povsem gladko...