minSdkVersion 19 cannot be smaller than version 22
When you are facing this error during ionic project building, it is as a result that cordova does not set minSdkVersion and targetSdkVersion correctly in app apk.
This was due to a bug in cordova-android@7.x.x but now solved with cordova-android updated versions.
Updating to cordova-android@8.x.x is required when facing this issue and it is pretty simple in doing that.
Lunch terminal inside project folder and run these two commands to upgrade:
//first remove cordova platform android
cordova platform remove android
//install cordova-android@8.x.x or higher
cordova platform add android@8.0.0
compile project again and it should work.
Read more about cordova versions from the official website