This hidden Android 14 feature reduces system resource use of preinstalled apps

If you judge every new Android release by what Google's marketing or your OEM's update changelog tells you, then you'll probably be disappointed by how few new features there seem to be. In my experience, every new Android release has a ton of new features and changes that never get talked about. I'm still discovering new changes myself, such as a feature that promises to reduce system resource use (and thus improve memory use/battery life) of preinstalled apps.

Starting in Android 14, whenever the OS "scans" system partitions during the initial boot and detects a new application that has an exported launcher activity (ie. it has a home screen icon you can tap to launch), the app will initially be put into a STOPPED state. This means that many preloaded apps that are launchable by the user won't consume system resources until the user actually launches them. (The reason this feature only applies to preinstalled apps that have a launcher activity is because, if it were to apply to apps without a launcher activity, then the user wouldn't have a way to bring the app out of the STOPPED state.)

This feature is enabled by default in AOSP through the configuration "config_stopSystemPackagesByDefault" being set to "true". However, Google allows OEMs to opt out of this feature by setting this configuration to "false" (via a Runtime Resource Overlay [RRO]). Furthermore, even if the OEM opts into the feature, they can still add selected apps to an allowlist which prevents the OS from setting their initial state to STOPPED.  The GMS bundle that OEMs integrate into their builds contains an XML (google-initial-package-stopped-states.xml) that allowlists several Google apps, including Chrome, Google Play Store, Docs, Maps, Messages, Files, Photos, YouTube Music, Calendar, Contacts, Gmail, Google, Google TV, and YouTube. Pixel phones have an additional XML (pixel_2017-initial-package-stopped-states.xml) that allowlists the Settings, Google Camera, and Personal Safety apps.

Google's description of this feature in the GMS Requirements doc states that it "significantly reduces the system resource (for example, memory or battery) usage." I hope that's true, but I don't have any data (from Google or my own benchmarks) to prove it. I'm curious to hear about your subjective experience on how the Android 14 release/update has fared in terms of memory use/battery life - let me know how it's been treating you!