The app's icon as it appears in the store is not defined by the app store settings. The app store settings only influence what your app looks like on the store page. The actual icon for the device is baked into the manifest file inside the APK.
I'm not familiar with Corona, but your build should have something called AndroidManifest.xml
within it that defines the metadata for the app. That includes the required permissions, starting Activity, and the icon for the application.
It might look something like this:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.yourname.yourapp">
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
<application
android:allowBackup="true"
android:icon="@drawable/logo"
android:label="@string/app_name"
android:theme="@style/AppTheme">
That attribute line within it:
android:icon="@drawable/logo"
specifies the resource name of the image to use as the icon