I will show you how is easy create a consistent image asset for your icon in a project React Native Android.
Open the Android Studio
After starting the project, you will have two folders inside the root folder, Android and iOS projects, open your Android Studio and select the Android folder.
Create an SVG asset
We need to create an element SVG at the project, I already have the SVG image, now, I need to create a specific XML SVG that Android understands. For to do this, click in the folder app -> res with the mouse second button and go to New -> Vector Assets.
And then, open your SVG image and set the configuration more likely for your case.
Create a new Image Asset
Now, click in the app -> res with the second mouse button and go to New -> Image Asset
The next step is to select the SVG image in Source Asset and use the Resize tool to adjust your image in the preview of the icon.
It's done! If you not change the ic_launcher name, probably you will overwrite the default icon React Native and then your app is done with the new icons for the most common Android icon version.