I got this warning from Google Console when I was uploading my app. What is the problem?
Your app currently targets API level 22 and must target at least API level 26 to ensure it is built on the latest APIs optimized for security and performance.
From August 2018, new apps must target at least Android 8.0 (API level 26).
From November 2018, app updates must target Android 8.0 (API level 26)."