Meu aplicativo está funcionando bem em dispositivos Lollipop, mas continua travando antes da versão Lollipop. Eu simplesmente implementei um banner add no meu aplicativo com o seguinte código na documentação do google

    // Request for Ads
           AdRequest adRequest = new AdRequest.Builder()

                  // Add a test device to show Test Ads
                 .addTestDevice(AdRequest.DEVICE_ID_EMULATOR)
                 .build();

         // Load ads into Banner Ads
         mAdView.loadAd(adRequest);

usando

    compileSdkVersion 23
    buildToolsVersion "23.0.1"

manifesto

  <meta-data
             android:name="com.google.android.gms.version"
             android:value="@integer/google_play_services_version" />

         <activity
             android:name="com.google.android.gms.ads.AdActivity"
          android:configChanges="keyboard|keyboardHidden
   |orientation|screenLayout|uiMode|screenSize|smallestScreenSize" />

Erro

 E/AndroidRuntime: FATAL EXCEPTION: main
 E/AndroidRuntime: Process: com.app.aggro, PID: 13257
 E/AndroidRuntime: java.lang.VerifyError: 
  com/google/android/gms/measurement/internal/zzv
 E/AndroidRuntime: at   
 com.google.android.gms.measurement.AppMeasurementContentProvider
.onCreate(Unknown Source)
E/AndroidRuntime:     at  
android.content.ContentProvider.attachInfo(ContentProvider.java:1656)
 E/AndroidRuntime:     at  
android.content.ContentProvider.attachInfo(ContentProvider.java:1627)
 E/AndroidRuntime:     at  
android.app.ActivityThread.installProvider(ActivityThread.java:5015)
E/AndroidRuntime:     at  
android.app.ActivityThread.installContentProviders
(ActivityThread.java:4589)
 E/AndroidRuntime:     at   
 android.app.ActivityThread.handleBindApplication
 (ActivityThread.java:4522)
E/AndroidRuntime:     at  
android.app.ActivityThread.access$1500(ActivityThread.java:151)
E/AndroidRuntime:     at  
android.app.ActivityThread$H.handleMessage(ActivityThread.java:1381)
E/AndroidRuntime:     at 
android.os.Handler.dispatchMessage(Handler.java:110)
E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:193)
  E/AndroidRuntime:     at  
android.app.ActivityThread.main(ActivityThread.java:5299)
E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native  
Method)
E/AndroidRuntime:     at  
java.lang.reflect.Method.invoke(Method.java:515)
E/AndroidRuntime:     at   
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run
(ZygoteInit.java:825)
 E/AndroidRuntime:     at   
 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:641)
E/AndroidRuntime:     at dalvik.system.NativeStart.main
(Native Method)

Meu arquivo Gradle é

 apply plugin: 'com.android.application'

 buildscript {
     repositories {
         maven { url 'https://maven.fabric.io/public' }
    }

    dependencies {
         classpath 'io.fabric.tools:gradle:1.+'
     }
 }
 repositories {
     mavenCentral()
     maven { url   
 "https://oss.sonatype.org/content/repositories/snapshots"}
        maven { url 'https://maven.fabric.io/public' }
        maven { url   
     "https://oss.sonatype.org/content/repositories/snapshots/" }
     maven { url 'https://dl.bintray.com/drummer-aidan/maven' }
 }
android {
     compileSdkVersion 23
     buildToolsVersion "23.0.1"

    defaultConfig {
         applicationId "com.app.aggro"
        minSdkVersion 15
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
     }
     buildTypes {
         release {
             minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-
android.txt'), 'proguard-rules.pro'
        }
    }


    dexOptions{
        incremental true
        javaMaxHeapSize "4g"
     }
    defaultConfig {
        multiDexEnabled true
    }
    packagingOptions {
         exclude 'META-INF/DEPENDENCIES'
         exclude 'META-INF/NOTICE'
         exclude 'META-INF/LICENSE'
         exclude 'META-INF/LICENSE.txt'
         exclude 'META-INF/NOTICE.txt'
     }
  }

 dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:23.0.1'
    compile('com.mikepenz:materialdrawer:3.0.9@aar') {
        transitive = true
     }
     compile('com.github.florent37:materialviewpager:1.1.0@aar') {
         transitive = true
    }


    compile('com.crashlytics.sdk.android:crashlytics:2.4.0@aar') {
        transitive = true;
     }
    compile 'com.google.android.gms:play-services:8.1.0'
     compile 'com.mcxiaoke.volley:library:1.0.+'
     compile 'com.google.code.gson:gson:2.3.1'
      compile 'com.marshalchen.ultimaterecyclerview:library:0.3.11'
     compile 'com.android.support:recyclerview-v7:22.2.0'
     compile 'com.android.support:cardview-v7:23.0.1'
     compile 'com.jpardogo.googleprogressbar:library:1.2.0'
      compile 'com.quinny898.library.persistentsearch:library:1.0.0-  
 SNAPSHOT'
     compile project(':storage')
     compile 'com.getbase:floatingactionbutton:1.10.0'
     compile 'com.parse.bolts:bolts-android:1.+'
      compile files('libs/activeandroid-3.1-beta.jar')
      compile 'com.android.support:design:23.0.1'
      compile 'it.neokree:MaterialTabs:0.11'
      compile 'com.miguelcatalan:materialsearchview:1.2.0'
  }

Por favor, me ajude a sair deste problema.