Update Android app

Hi guys, I'm a 3D/VFX artist and I have created and animation which I'd like to sell as a live wallpaper on play store, I created the app using CLWC ([login to view URL]) however it seems to be a bit outdated and when I try to upload my .APK to the market an error messege pops out saying that my API interface level is too low (it's 19, should be 26). So basically the job would be to update the api level interface or make the app from scratch, I don't want any interactions in app, only for the user to open the app and activate wallpaper with one button. I provide the video (it is about 10 mb) and the .apk (if you're upgrading the app from CLWC rather than making it from begging to end). I don't want any adds. What I expect from the app is for me to be able to upload it to play store and run without issues. Possible more work in the future if the app turns out profitable.