Vulkan Video Backend isn't supported?

[degasus]

Is it a nvidia GPU? If not, the drivers are likely bad.

Edit: Oh, it's not android Nougat, so the chance is even worse to get vulkan running :/

To be honest, there is no need to care about Vulkan. The GL driver is likely better. I think you'll see a good performance upgrade on the android-N update. Else, dolphin is hard to use fast.