Quando executo meus códigos, o Adroid studio dá esse erro

meu arquivo gradle como abaixo e o Android Studio v2.2 gradle é 'com.android.tools.build:gradle:2.2.0-alpha1'

    apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.2"

    packagingOptions {

        exclude 'META-INF/DEPENDENCIES'
    }

    defaultConfig {
        applicationId "com.asd.asd"
        minSdkVersion 14
        targetSdkVersion 23
        versionCode 9
        versionName "1.3.4"
        multiDexEnabled true
    }

    buildTypes {
        release {
            debuggable false
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
        }
    }
    dexOptions {

        javaMaxHeapSize "4g"
        jumboMode true
        preDexLibraries false
    }
}

    dependencies {
        compile project(':mPChartLib')
        compile fileTree(dir: 'libs', include: ['*.jar'])
        testCompile 'junit:junit:4.12'
        compile 'com.android.support:appcompat-v7:23.1.1'
        compile 'com.google.code.gson:gson:2.3.1'
        compile files('libs/commons-httpclient-3.1.jar')
        compile files('libs/signpost-commonshttp4-1.2.1.2.jar')
        compile files('libs/signpost-core-1.2.1.2.jar')
        compile files('libs/pushwoosh-4.0.4.jar')
        compile files('libs/httpcore-4.4.4.jar')
        compile files('libs/httpclient-4.5.2.jar')
        compile 'com.google.android.gms:play-services:9.0.0'



    }


05-30 20:41:50.785 14551-14551/com.asd.asd/AndroidRuntime: FATAL EXCEPTION: main                                                                     Process: com.asd.asd, PID: 14551
                                                                         java.lang.NoClassDefFoundError: com.google.firebase.FirebaseOptions
                                                                             at com.google.firebase.FirebaseApp.zzbu(Unknown Source)
                                                                             at com.google.firebase.provider.FirebaseInitProvider.onCreate(Unknown Source)
                                                                             at android.content.ContentProvider.attachInfo(ContentProvider.java:1638)
                                                                             at android.content.ContentProvider.attachInfo(ContentProvider.java:1609)
                                                                             at com.google.firebase.provider.FirebaseInitProvider.attachInfo(Unknown Source)
                                                                             at android.app.ActivityThread.installProvider(ActivityThread.java:5008)
                                                                             at android.app.ActivityThread.installContentProviders(ActivityThread.java:4582)
                                                                             at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4522)
                                                                             at android.app.ActivityThread.access$1500(ActivityThread.java:151)
                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1381)
                                                                             at android.os.Handler.dispatchMessage(Handler.java:110)
                                                                             at android.os.Looper.loop(Looper.java:193)
                                                                             at android.app.ActivityThread.main(ActivityThread.java:5292)
                                                                             at java.lang.reflect.Method.invokeNative(Native Method)
                                                                             at java.lang.reflect.Method.invoke(Method.java:515)
                                                                             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824)
                                                                             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
                                                                             at dalvik.system.NativeStart.main(Native Method)

idont usar qualquer aplicativo firebase, mas eu tenho esse erro. então eu tento muitas técnicas que são encontradas na internet. mas observando mudanças.

você pode me ajudar pls