Как добавить admob баннер в DrawerLayout?

<?xml version="1.0" encoding="utf-8"?>

<androidx.drawerlayout.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:ads="http://schemas.android.com/apk/res-auto"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:openDrawer="start">

        <include
            layout="@layout/app_bar_main"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

        <com.google.android.material.navigation.NavigationView
            android:id="@+id/nav_view"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="start"
            android:fitsSystemWindows="true"
            app:headerLayout="@layout/nav_header_main"
            app:menu="@menu/activity_main_drawer" />

        <com.google.android.gms.ads.AdView

            android:id="@+id/adView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_centerHorizontal="true"
            ads:adSize="SMART_BANNER"
            ads:adUnitId="UNIT_ID"/>

</androidx.drawerlayout.widget.DrawerLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:ads="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context=".MainActivity"
    tools:showIn="@layout/app_bar_main"
    android:id="@+id/content_main">
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Hello World!" />

        <com.google.android.gms.ads.AdView

            android:id="@+id/adView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_centerHorizontal="true"
            ads:adSize="SMART_BANNER"
            ads:adUnitId="UNIT_ID"/>
    </RelativeLayout>
</RelativeLayout>

public class Ads {

    public static void showBanner(final Activity activity) {
        final AdView mAdView = (AdView) activity.findViewById(R.id.adView);
        AdRequest adRequest = new AdRequest.Builder().build();
        mAdView.loadAd(adRequest);

        mAdView.setAdListener(new AdListener() {
            @Override
            public void onAdClosed() {
                super.onAdClosed();
                //do something on ad is closed
            }

            @Override
            public void onAdFailedToLoad(int i) {
                super.onAdFailedToLoad(i);
                //do something if ad failed to load
            }

            @Override
            public void onAdLeftApplication() {
                super.onAdLeftApplication();
            }

            @Override
            public void onAdOpened() {
                super.onAdOpened();
                setupContentViewPadding(activity, mAdView.getHeight());
            }

            @Override
            public void onAdLoaded() {
                super.onAdLoaded();
            }

            @Override
            public void onAdClicked() {
                super.onAdClicked();
            }

            @Override
            public void onAdImpression() {
                super.onAdImpression();
            }
        });
    }
    public static void setupContentViewPadding(Activity activity, int padding) {
        View view = activity.findViewById(R.id.drawer_layout); // id был добавлен в этом слое на момент запуска
        view.setPadding(view.getPaddingLeft(), view.getPaddingTop(), view.getPaddingRight(), padding);
    }
}