"Compiled for an older Android version" alert

I’m creating an Android game and when running it on one of my friend’s devices, right after the prompt for permissions, I got an alert reading (translating from my mother tongue so it’s probably not 1:1 to an English equivalent but the meaning stays):


This application has been compiled for an older version of Android and may not work properly. Check for updates of contact the creator.

How can I fix this issue? I have minimum SDK and target SDK set to 19, NDK API to android-19 and SDK API to matchndk. It’s not like this is an educated choice though, I just saw the engine (I’m using 4.17 cause this is kind of a legacy project that I’m just finishing up) suggesting 19 for GearVR so I went with that to not alienate anyone (this is a VR game, for Cardboard/Daydream/what have you). Should I change the figures? To what values?