android studio 3.4.1 and google admob change

In build.gradle (Module:app) change

...

    buildTypes {

        release {

            minifyEnabled false

            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'

        }

    }

...

dependencies {

   implementation 'com.android.support:appcompat-v7:28.0.0'
   implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.google.android.gms:play-services-ads:17.2.1'

In AndroidManifest.xml add
<manifest>
   
<application>
...
       
<meta-data
           
android:name="com.google.android.gms.ads.AD_MANAGER_APP"
           
android:value="true"/>

   
</application>
</manifest>