Here's some topics talking about it:
1280px * 720px will be acceptable if you publish only for Apple Products or PC's and etc but certainly "Not Android". Actually it is still playable and good performance in Android 4.4 (Kitkat) and above if it is high in specs.
But the Safe bet will be 854px & 480px: You won't be having problem in your optimized game even in Android 4.2
Safest bet: 640x360. This is actually recommended more for Pixel Games only. But assurance that it will work even on Android 4.0 devices.
1980px x 1080px : Trust me don't try it. It will be very hard even for Apple Products and Android Phones can't render 1080px games without fps drop.