Best Android icons were in Android 5.0, and went downhill from that.
Maybe I'm just being curmudgeonly, but I think icon design went downhill in about the mid-nineties. Classic Mac OS and Windows 95 haven't really been bested in terms of icon design clarity... and don't get me started about the loss of the Classic Mac OS Finder and its purely spatial metaphor. Not all design work is progress.
The only apps that look right on your screen are the ones that have a dedicated mobile graphics department...
But looking more closely, it seems like this is for Play Store icons, not the APK icons on your phone. Which makes me go... meh, whatever.
Also why are we trying to make all these icon borders the same in the first place? The silhouette is one of the first things our brain sees and processes; that's why it's such an important part to pay attention to in art. Making it all the same makes it that much more difficult to differentiate the icons from one another, which frustrates me as a user.
It's an absolute nightmare to develop on an iPhone X and try to get screenshots onto the store. You're required to have 5.5" screenshots, which means an iPhone 8 Plus. The guidelines specifically say your app has to be designed to work on all screen sizes, but I can't submit screenshots taken on my iPhone X or XS and submit them to the store. I have to resize them, which means cutting off the top and bottom to make it wide enough to fit the resolution of the iPhone 8 Plus. Apple, a genius of a tech company, cannot figure out how to display screenshots from an iPhone X on an iPhone 8, but they can show iPhone 8 screenshots on an iPhone X. My app is location-based, so screenshots have to be taken on-site... but I don't own an iPhone 8 Plus. I own an iPhone XS and an iPhone 8. But I can't use the screenshots from either without editing them to chop off the top and bottom.
Google gets it a bit better in that you can upload any screenshots you want of any size or resolution, but they require a separate icon upload. And while Apple's icons need to be 1024x1024, Google needs them to be exactly 512x512. Again, a genius tech company cannot figure out on their own website how to resize an image before it gets saved.
Not to mention Apple wants promo videos in portrait mode, even though iMovie does not support portrait mode videos. But Google wants your promos hosted on Youtube, which prefers landscape videos. So now every promo has to be shot and edited twice.
Changing from a round icon to a square icon is the least of my worries.
In my case they've never rejected the screenshots for having done that (and it clearly shows you've used the Simulator: they have "Carrier" as the carrier name).
So why does Apple make me submit a video of my app working in the real world if they can just spoof the location from their end?