I have successfully changed the App Icon for the App by replacing the file with the files I downloaded from here.
I replaced [mipmap-hdpi, mipmap-mdpi, mipmap-xhdpi, mipmap-xxhdpi, mipmap-xxxxhdpi] folders with new ones in the android->app->src->main->res path of my project.
Any help will be highly appreciated.
Solution 1: Sunil
Please check manifest file.
<application android:name="io.flutter.app.FlutterApplication" android:label="flutter" android:icon="@mipmap/app_logo">
You have to change icon name here.
Solution 2: Paul Kastel
I had exactly the same issue. I rebooted my smartphone and it worked as it was suggested in related topics. After restart the icon is displayed as it should everywhere.
I attach related links: