I am working on an install referral in which need to avoid crediting users for multiple app installs. Settings.Secure.ANDROID_ID looks to solve the issue. In the below URL it is mentioned not to use hardware identifiers and need READ_PRIVILEGED_PHONE_STATE permission to use this
https://developer.android.com/training/articles/user-data-ids.html
I am able to get the ANDROID_ID without asking any permission in Android 10 devices. Is Android_ID a hardware identifier ? Is there a mistake in this document.
I m aware that there are few devices which returns null and same value for all models. Apart from this is it safe to depend on this or it is gonna change in future,