I place the banner ad on the top of the main activity, but when the app switch app open ad shows and violate the AdMob (policy )
Is that possible to change the background of the app open ad, as you know that by default app open app ad's background is transparent, As a result, when the app open ad shows, the banner ad is also showing in the background.
Finally, After a lot of research, I found the answer,
First, create a theme in style.xml or theme.xml file( make app open ad background black)
<style name="Theme.AppThemeNoActionBar.AdTheme" >
<item name="android:background">@color/black</item>
<item name="android:windowBackground">@color/black</item>
<item name="android:windowExitAnimation">@null</item>
<item name="android:windowEnterAnimation">@null</item>
</style>
and declare the activity on the manifest.xml file, and apply the theme
<activity
android:name="com.google.android.gms.ads.AdActivity"
android:theme="@style/Theme.AppThemeNoActionBar.AdTheme"
tools:replace="android:theme"/>