react-native-firebase/bridge/android/build.gradle

buildscript {
  repositories {
    jcenter()
    google()
    maven {
      url 'https://maven.fabric.io/public'
    }
  }
  dependencies {
    classpath 'com.android.tools.build:gradle:3.1.2'
    classpath 'com.google.gms:google-services:3.2.1'
    classpath 'com.google.firebase:firebase-plugins:1.1.1'
    classpath 'io.fabric.tools:gradle:1.25.1'
  }
}

allprojects {
  repositories {
    mavenLocal()
    jcenter()
    google()
    maven {
      url "$rootDir/../node_modules/react-native/android"
    }
  }
}

subprojects {
  ext {
    compileSdk = 27
    buildTools = "27.0.3"
    minSdk = 18
    targetSdk = 26
  }

  afterEvaluate { project ->
    if (!project.name.equalsIgnoreCase("app")
      && project.hasProperty("android")) {
      android {
        compileSdkVersion compileSdk
        buildToolsVersion buildTools
        defaultConfig {
          minSdkVersion minSdk
          targetSdkVersion targetSdk
        }
      }
    }
  }
}