With the release of Android 10 back in 2019, Google debuted Project Mainline, an initiative that lets Google directly deliver updates to key Android components. The goal was to bolster security, protect privacy, and improve developer consistency by standardizing certain system components and delivering updates to them on a consistent schedule. The mechanisms of Project Mainline are opaque to the user and updates are delivered in batches with no changelog. The only thing the user sees is that a “Google Play System Update” is pending on their device, and after downloading a small package, they’re prompted to restart to apply the changes. After downloading the latest update today, some users have noticed that the boot animation now shows the percent completion of the updating process.
Twitter user @jas0nsg was the first to spot this new functionality, and he shared the following video with us demonstrating it on his Pixel 5 which received a Google Play System Update today:
XDA Recognized Developer luca020400 also spotted the percent progress on his Pixel 5 following a Google Play System Update. We believe this functionality was triggered through an updated APEX module, though we don’t know exactly which one is responsible. Code for this functionality was committed to AOSP in early February, but at the time, Google engineers said the code was merely to show a proof of concept of the feature. Luca020400 believes the percent progress in the boot animation is only shown during updates to the ART module, which was added in Android 12. The reason, he says, is because applying updates to ART requires additional steps after the reboot.
In any case, this is a small functional update that landed on a few Pixel phones running Android 12 today. If you spot a Google Play System Update on your device and want to see what’s changed, you can run the following command before and after the update to compare the version codes of each APEX module:
pm list packages --apex-only --show-versioncode -f