I was having the same issue but finally managed to fix it. Are you testing it on a Xiami phone? It almost seems like the android phone is using some of the icons from ios resources. Although I’m not really sure about that.
I actually went through all .png files in the project folder and I found the sample icon in ios resources. So I regenerated the icons for ios (even though I have an android app) using ionic cordova resources ios, uninstalled the app in the phone and installed it again. And it worked!
I double checked all the .png files again and haven’t the sample icon anywhere.
i am also have the same issue, now i am solved. i am giving the steps below for solution.
1. Remove platforms folder and add android platform, it will give default android image for app
2. If you don't have a resource folder run command "ionic resources" it will generate a resource folder with Icons and Splash folder.
3. Add images in resources/android/icon/drawable-ldpi-icon.png and resources/android/splash/drawable-land-ldpi-screen.png and add path in config.xml
4.npm install -g ionic