I'm trying to get rid of this white background that appears around my logo.

I was able to change the background from here android/app/src/main/res/drawable/launch_background.xml:
<?xml version="1.0" encoding="utf-8"?>
<!-- Modify this file to customize your launch splash screen -->
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@color/back_color"/>
<!-- You can insert your own image assets here -->
<item>
<bitmap
android:gravity="center"
android:src="@drawable/logo"/>
</item>
</layer-list>
but the image is showing white background even though the image in the asset has no white background. How can I remove this white background?
Note: I'm using Flutter in Android Studio
change it like this: