com.google.android.packageinstaller
com.google.android.packageinstaller
Google package installer. Seems to replace com.android.packageinstaller on newer phones. It is strangely not needed on older devices (you can still install APKs without it by using the AOSP package installer) but since Android 9, it also handles permissions control and could bootloop your device if removed.
On Android 8.1, disabling the app also disabled the ‘Permissions’ settings within all the apps. Besides that, I couldn’t install an ‘.apk’ file download from outside the Play Store.
Source: https://source.android.com/docs/core/architecture/modular-system/permissioncontroller.