title: library com.google.android.gms:play-services-basement is being requested by various other libraries at [[15.0.1,15.0.1]], but resolves to 16.0.1
body: <p><strong>When syncing the project this error is appearing:</strong> </p>
  
  <blockquote>
    <p>The library com.google.android.gms:play-services-basement is being
    requested by various other libraries at [[15.0.1,15.0.1]], but
    resolves to 16.0.1.</p>
    
    <p>Disable the plugin and check your dependencies tree using <code>./gradlew
    :app:dependencies</code>.</p>
  </blockquote>
  
  <p>This is my <code>build.gradle</code> Project file:</p>
  
  <pre><code>// Top-level build file where you can add configuration options common to all sub-projects/modules.
  
  buildscript {
  
  repositories {
      google()
      jcenter()
      maven {
          url 'https://maven.fabric.io/public'
      }
  }
  dependencies {
      classpath 'com.android.tools.build:gradle:3.2.1'
      classpath 'com.google.gms:google-services:4.1.0'
      classpath 'io.fabric.tools:gradle:1.25.4'
  
      // NOTE: Do not place your application dependencies here; they belong
      // in the individual module build.gradle files
  }
  }
  
  allprojects {
  repositories {
      google()
      jcenter()
      maven {
          url 'https://maven.google.com/'
      }
  }
  }
  
  task clean(type: Delete) {
       delete rootProject.buildDir
  }
  </code></pre>
  
  <p>And this is my <code>build.gradle</code> app file: </p>
  
  <pre><code>import com.google.gms.googleservices.GoogleServicesPlugin
  
  apply plugin: 'com.android.application'
  apply plugin: 'io.fabric'
  
  android {
  compileSdkVersion 27
  defaultConfig {
      multiDexEnabled true
      applicationId "com.example.myexampleapp"
      minSdkVersion 19
      targetSdkVersion 27
      versionCode 13
      versionName "0.1.13"
      testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
      vectorDrawables.useSupportLibrary = true
  }
  buildTypes {
      release {
          minifyEnabled false
          proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
      }
  }
  }
  
  dependencies {
  implementation 'com.google.firebase:firebase-core:16.0.4'
  implementation fileTree(dir: 'libs', include: ['*.jar'])
  implementation 'com.android.support:appcompat-v7:27.1.1'
  implementation 'com.android.support:design:27.1.1'
  implementation 'com.android.support:cardview-v7:27.1.1'
  implementation 'com.android.support.constraint:constraint-layout:1.1.3'
  implementation 'com.google.firebase:firebase-firestore:17.1.1'
  implementation 'com.android.support:support-v4:27.1.1'
  implementation 'com.firebaseui:firebase-ui-auth:4.1.0'
  implementation 'com.firebaseui:firebase-ui-firestore:4.1.0'
  implementation 'com.crashlytics.sdk.android:crashlytics:2.9.5'
  implementation 'com.google.android.gms:play-services-auth:16.0.1'
  testImplementation 'junit:junit:4.12'
  androidTestImplementation 'com.android.support.test:runner:1.0.2'
  androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
  }
  apply plugin: 'com.google.gms.google-services'
  </code></pre>
  
  <p><strong>What I have tried:</strong> </p>
  
  <ul>
  <li>Following these instructions: <a href="https://stackoverflow.com/questions/50577437/com-google-android-gmsplay-services-measurement-base-is-being-requested-by-vari">com.google.android.gms:play-services-measurement-base is being requested by various other libraries</a></li>
  <li>Updating all kinds of libraries to the newest versions</li>
  </ul>
  
  <p><strong>Thank you for your help!</strong></p>
  
  <p><strong>Update:</strong>
  This is what I currently have in my dependencies:</p>
  
  <pre><code>dependencies {
  api "com.android.support:appcompat-v7:28.0.0"
  api "com.android.support:customtabs:28.0.0"
  api "com.android.support:support-v4:28.0.0"
  api "com.android.support:cardview-v7:28.0.0"
  api "com.android.support:design:28.0.0"
  api "com.android.support.constraint:constraint-layout:1.1.3"
  
  api "com.crashlytics.sdk.android:crashlytics:2.9.5"
  api "com.google.android.gms:play-services-base:16.0.1"
  api "com.google.android.gms:play-services-auth:16.0.1"
  
  api "com.google.firebase:firebase-core:16.0.5"
  api "com.google.firebase:firebase-auth:16.0.5"
  api ("com.google.firebase:firebase-firestore:17.1.2") {
      exclude group: "com.squareup.okhttp", module: "okhttp"
  }
  api ("com.firebaseui:firebase-ui-firestore:4.1.0") {
      exclude group: "com.google.code.gson", module: "gson"
  }
  api ("com.firebaseui:firebase-ui-auth:4.1.0") {
      exclude group: "com.google.code.gson", module: "gson"
  }
  implementation fileTree(dir: 'libs', include: ['*.jar'])
  }
  </code></pre>
  
  <p>And this is the error that I am getting:</p>
  
  <blockquote>
    <p>error: cannot find symbol class IFlagProvider</p>
  </blockquote>