How to change the background color of the ads banner in Android?

I use the library 'com.google.android.gms: play-services-ads: 19.1.0' for advertising, I create a banner as follows: https://developers.google.com/admob/android/banner/adaptive so that it always turned out to be the full width of the screen and everything works well, but sometimes black lines appear enter image description here

please tell me how can I remove them? I tried transparent styles and setting the background color,

android: theme = "@ style / TranslucentTheme" android: background = "@ color / transparent"

In xml and through the code, and nothing helps.