If a recent sighting on Android Gerrit is to be believed, the process of installing updates on Android devices could be receiving a significant speed boost. The listing discusses a new feature called “Resume on Reboot” which would allow certain phones to complete the update process without requiring a manual unlock.
Currently, an OTA update does not finish without forcing the user to unlock their phone. This step occurs once the device has been rebooted — after the reboot, many apps still need to update to work properly with the new software. This means that even if you leave your phone alone for several hours while the install occurs, the process won’t actually finish until you unlock the device and allow all your apps to update.
Resume on Reboot changes that. The new feature would store your login information and simply “unlock” the device for you. This would allow the entire update to proceed without any intervention by the user. However, this functionality requires a HAL (Hardware Abstraction Layer) called IRebootEscrow. That isn’t on every device, so this won’t be a universal feature for Android phones. Resume on Reboot is being tested on the Pixel 4 and should be available to the public in a future update.