Nexus 5x, OPP5.170921.005

- Steps to reproduce the problem (including sample code if appropriate).
Try to use Admob interstitial ads , as shown here:

https://developers.google.com/admob/android/quick-start
https://developers.google.com/admob/android/interstitial

Here's a snippet of code that worked fine for me for a long time:

MobileAds.initialize(context, context.getString(R.string.admob_app_id));
mInterstitialAd = new InterstitialAd(context);
mInterstitialAd.setAdUnitId(context.getString(R.string.admob_ad_unit_id));
mInterstitialAd.setAdListener(new AdListener() {
...
@Override
public void onAdLoaded() {
super.onAdLoaded();
Log.d("AppLog", "onAdLoaded");
show(context);
}
});
if (!mInterstitialAd.isLoading() && !mInterstitialAd.isLoaded())
mInterstitialAd.loadAd(new AdRequest.Builder().build());

Updated everything you can on the SDK, IDE, etc...
Run the app on Android 7.0 and 8.1.

- What happened.
On version 7.0 (emulator), it worked fine.

On 8.1 (emulator and device), it crashed with this exception:

10-28 14:01:01.394 4523-4523/... I/Ads: Ad opening.
10-28 14:01:01.400 1606-2154/? E/ActivityManager: Activity Manager Crash. UID:10080 PID:4523 TRANS:63
java.lang.IllegalStateException: Only fullscreen activities can request orientation
at com.android.server.am.ActivityRecord.setRequestedOrientation(ActivityRecord.java:2189)
at com.android.server.am.ActivityManagerService.setRequestedOrientation(ActivityManagerService.java:4975)
at android.app.IActivityManager$Stub.onTransact(IActivityManager.java:1101)
at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:2927)
at android.os.Binder.execTransact(Binder.java:697)

10-28 14:01:01.403 4523-4523/... D/AndroidRuntime: Shutting down VM
10-28 14:01:01.406 4523-4523/... E/AndroidRuntime: FATAL EXCEPTION: main

java.lang.RuntimeException: Unable to start activity ComponentInfo{.../com.google.android.gms.ads.AdActivity}: java.lang.IllegalStateException: Only fullscreen activities can request orientation

- What you think the correct behavior should be.
Should work as before.

Since I need an answer of how to solve this, I wrote about it on StackOverflow too:
https://stackoverflow.com/q/46992843/878126

Please also run "adb bugreport" and archive the output.