// app/build.grandle set -->
implementation "com.google.android.gms:play-services-base:16.0.1"
    implementation "com.google.firebase:firebase-core:16.0.1"
    implementation "com.google.firebase:firebase-database:16.0.1"

// build.grandle
configurations.all {
            resolutionStrategy.eachDependency { DependencyResolveDetails details ->
                def requested = details.requested
                if (requested.group == 'com.google.android.gms') {
                    details.useVersion '16.0.1'
                }
                if (requested.group == 'com.google.firebase') {
                    details.useVersion '16.0.1'
                }
            }
        }
//grandle.properties
googlePlayServicesVersion=16.0.1