错误：原因：无法找到有效的认证路径到请求的目标

我如何解决这个问题

我也在添加我的Gradle文件

apply plugin: 'com.android.application'
android {
compileSdkVersion 25
buildToolsVersion "25.0.2"
defaultConfig {
    applicationId "com.sample.myapplication"
    minSdkVersion 16
    targetSdkVersion 22
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'),'proguard-rules.pro'
    }
} } dependencies {
compile fileTree(dir: 'libs',include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2',{
    exclude group: 'com.android.support',module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:23.4.0'
compile 'com.android.support:design:23.4.0'
compile 'com.android.support:palette-v7:23.4.0'
testCompile 'junit:junit:4.12'
// FireBase
compile 'com.google.firebase:firebase-messaging:9.0.0'
}//Add this line
apply plugin: 'com.google.gms.google-services'

和项目级别Gradle文件

buildscript {
repositories {
    jcenter()
}
dependencies {
    classpath 'com.android.tools.build:gradle:2.2.3'
    classpath 'com.google.gms:google-services:3.0.0'
}
}
allprojects {
repositories {
    mavenCentral()
    jcenter{ url "http://jcenter.bintray.com/" }
    maven { url "https://jitpack.io" }
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}