My question is how to change default APK installation icon (not the one onto desktop after installing the app). I need to change the default green robot icons which I see while regular browsing of apk's.
When creating an AIR application, both Android and iOS icons are all stated under the <icon> tag in your yourapp-app.xml file.
You just need to make sure all sizes are stated, and your icon will appear both in the installation APK icon and on the device screen.
Here are all the sizes you need to define in your yourapp-app.xml file:
<application xmlns="http://ns.adobe.com/air/application/25.0">
....
<icon>
<image36x36>assets/icon_036.png</image36x36>
<image48x48>assets/icon_048.png</image48x48>
<image57x57>assets/icon_057.png</image57x57>
<image72x72>assets/icon_072.png</image72x72>
<image76x76>assets/icon_076.png</image76x76>
<image96x96>assets/icon_096.png</image96x96>
<image114x114>assets/icon_114.png</image114x114>
<image120x120>assets/icon_120.png</image120x120>
<image512x512>assets/icon_512.png</image512x512>
</icon>
....
</application>