Since 8.x Nativescript ships with the adaptive icons - since the old icons are outdated on more recent android phones, and usually look weird
1.Open a project in Android Studio and in the Project Explorer pane right-click on the app directory or any of the directories inside the app directory. In the context menu that opens select New > Image Asset
2.Once Asset Studio opens you'll see the new default app icon
3.The main thing to know about adaptive icons is that there are two layers, a foreground and background. The default foreground will be titled ic_launcher_foreground.xml and it is an SVG. Go ahead and click the ... button next to the path (image below) and select your app icon that you're going to use.
4.Now you can go ahead and set the other settings for your icon such as trim and the resize percentage. You'll also be able to change the default green background layer, select the Background Layer tab and you can repeat the same process. From experience, in a lot of cases you can use the Color radio button to set the color you'd like to use for your background layer.
5.Once you are finished with your icon configuration you can complete the wizard which will generate the various resources needed for your app. The new files will be located under the android app directory in src/main/res/ where you should see several mipmap- directories.
6.Now move all the files in mipmap- directories to your Nativescript's App_Resources mipmap folder
7.Once you have copied over the newly created icon files to the NativeScript project there is one final change you need for your application. The only change is to set the android:icon value to @mipmap/ic_launcher which is the resource location of the new files we added from the Android project from Android Studio.
Hope this helps to solve your issue