Could not collect Google Advertising ID というエラーが出て、広告がちゃんと出ない

以下のようなエラーが出た。

[DataCollector] Could not collect Google Advertising ID - this will negatively impact your eCPMs! Please integrate the Google Play Services SDK into your application. More info can be found online at http://developer.android.com/google/play-services/setup.html. If you're sure you've integrated the SDK and are still seeing this message, you may need to add a ProGuard exception: -keep public class com.google.android.gms.** { public protected *; }
com.google.android.gms.common.GooglePlayServicesIncorrectManifestValueException: The meta-data tag in your app's AndroidManifest.xml does not have the right value. Expected 12451000 but found 8298000. You must have the following declaration within the element:
at com.google.android.gms.common.GooglePlayServicesUtilLight.isGooglePlayServicesAvailable(com.google.android.gms:play-services-basement@@17.6.0:32)
at com.google.android.gms.common.GoogleApiAvailabilityLight.isGooglePlayServicesAvailable(com.google.android.gms:play-services-basement@@17.6.0:2)
at com.google.android.gms.ads.identifier.AdvertisingIdClient.zza(Unknown Source:17)
at com.google.android.gms.ads.identifier.AdvertisingIdClient.zza(Unknown Source:17)
at com.google.android.gms.ads.identifier.AdvertisingIdClient.getAdvertisingIdInfo(Unknown Source:47)
at com.applovin.impl.sdk.m.c(Unknown Source:15)
at com.applovin.impl.sdk.m.j(Unknown Source:2)
at com.applovin.impl.sdk.e.f.run(Unknown Source:6)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:462)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:301)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.lang.Thread.run(Thread.java:919)

ちなみにメディエーションツールにはMAXを使っている。

mBaaSとしてNCMBを使っているのだけれど、そちらをインストールしたときに、Plugin/Android/res/values/version.xmlが追加され、そこに

8298000

という記載があった。ここに書かれた数値を、8298000から12451000に変えたらエラーが出なくなりました。