I got the same question and I asked this to android developer support, got their reply as below

You may update your icon displayed in Google Play by uploading the updated icon to the Store Listing tab of the Play Console.However, once the app has been installed on a device, the icon will be displayed from the graphic assets of the APK as defined in the “android:icon=” manifest property. The icon that is displayed in the apps list in the Play Console is also taken from the APK.

To display a different icon, please update the icon image file in your APK. To find the location of the existing icon, you can use the manifest property or check your APK’s “res” folder.

So I got the icon updated at app store without submitting the app again (Note: I have already submitted with the icon change, so what I was looking to is how this can be reflected to App store icon). Please see screenshots attached for getting someone who is needy.

Yes, you can change the name and logo whenever you want by changing android:label and android:logo attribute of your application tag in AndroidManifest.xml file.

But, you can't change Package name once you uploaded app on play store.

You can Upload custom brand assets, screenshots, and videos to highlight what's great about your app. Provide a localized description, add notes about the latest version, and more. You can update your store listing at any time.

Upload instantly publish

From the Developer Console you can quickly upload and publish a release-ready Android application package file. The app is a draft until you publish it, at which time Google Play makes your store listing page and app available to users—your app appears in the store listings within hours, not weeks.

Once your app is published, you can update it as often as you want: Change prices, configuration, and distribution options at any time, without needing to update your app binary.

As you add features or address code issues, you can publish an updated binary at any time. The new version is available almost immediately and existing customers are notified that an update is ready for download. Users can also accept automatic updates to your app, so that your updates are delivered and installed as soon as you publish them. You can unpublish your apps app at any time.

update

put your image in drawable folder and set in manifest file...like as

 <application android:icon="@drawable/icon" android:label="@string/app_name" > ....  </application>  

Note:

The 512x512 icon you upload to the developer console (when you publish the app) is the one that will be seen in Google Play. The 36x36, 48x48, 72x72, and 96x96 icons you put in your drawable resource folders are what will show up on the device homescreen/app drawer.