title: Fabric's Crashlytics with Firebase can't be disabled for DEBUG builds
body: <p>I have an app that utilises Fabric's Crashlytics via Firebase.
  The following is the first thing executed in my Applications onCreate</p>
  
  <pre><code>CrashlyticsCore crashlyticsCore = new CrashlyticsCore.Builder()
      .disabled(BuildConfig.DEBUG)
      .build();
  Fabric.with(this, new Crashlytics.Builder().core(crashlyticsCore).build());
  </code></pre>
  
  <p>Nonetheless, the crashes are submitted in <code>DEBUG == true</code> mode.</p>
  
  <p>I use the following versions</p>
  
  <p>in my build.gradle
  <code>classpath "io.fabric.tools:gradle:1.25.1"</code></p>
  
  <p>in my app/build.gradle
  <code>implementation "com.crashlytics.sdk.android:crashlytics:2.9.1"</code></p>
  
  <p>Unfortunately the crashes still get reported. Any ideas, what I am doing wrong?</p>