In my app I use some implementation to check, if the app was downloaded from Google Play Store. Otherwise it does not start. For this I use getInstallerPackageName() by checking if the name is com.android.vending.
This basically works on all of my devices, but in Google Play the pre-launch report tells me, that 2 of 9 devices return null from this method. Now there are two possibilities. Either this method returns sometimes null, even if it's downloaded from Google Play Store, or it is null, because the pre-launch report somehow causes it. When it is null, this would usually mean that the apk was not downloaded from Google Play Store. I have no idea how this pre-launch report works in the background. Maybe the APK is somehow processed in the background before it will be deployed on these "test devices". Does anybody have a clue if it is possible that this value is null, even if it is downloaded from Google Play Store?