@sonnyhes, I was able to use it for the main app icon (rounded masked icon on Oreo default launcher).
Just follow the Android tutorial to create the image asset.
And copy the files generated to your AIR SDK folder:
if you don't use the Legacy image icons and use plain svg/xml just copy the contents of:
res/drawable/
res/mipmap-anydpi-v26/
res/values/
Then in you air manifest xml, you will only be able to define android:roundIcon attribute, otherwise, if you include the regular icon there, the compiler will fail with "Android attribute is not allowed to be overridden"
<application android:enabled="true"
android:allowClearUserData="true"
android:allowBackup="true"
android:roundIcon="@mipmap/ic_launcher_round" >
In this case, @mipmap/ic_launcher_round should be in your AIR SDK air_sdk/lib/android/lib/resources/app_entry/res/mipmap-anydpi-v26/ic_launcher_round.xml