AdvertisingIdClient , and its related classes are also in much smaller
com.google.android.gms:play-services-basement:8.3.0
if you use Google Play 8.3 services. Until now, you are correct that it was part of play-services-ads .
In any case, it is strongly recommended that you use ProGuard to remove unused code from your application before sending retail versions of your application.
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