when i build my android project,I've the following error
Error:In <declare-styleable> FontFamilyFont, unable to find attribute android:fontVariationSettings
Before I could build the project very well, and I have not modified any configuration, the following is my related configuration
project build.gradle
buildscript {
    repositories {
        mavenCentral()
        jcenter{
            url 'http://jcenter.bintray.com/'
        }
        google()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'
        classpath 'org.greenrobot:greendao-gradle-plugin:3.2.1'
        classpath 'me.tatarka:gradle-retrolambda:3.2.4'
    }
}
allprojects {
    repositories {
        jcenter()
        mavenCentral()
        maven { url "https://jitpack.io" }
        maven{ url 'https://download.01.org/crosswalk/releases/crosswalk/android/maven2' }
        google()
    }
}
task clean(type: Delete) {
    delete rootProject.buildDir
}
app build.gradle
android {
    compileSdkVersion 27
    buildToolsVersion "27.0.2"
    defaultConfig {
        applicationId "com.bsyx.callsystem"
        minSdkVersion 19
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        multiDexEnabled true
    }
}
dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:support-v4:27.1.0'
    compile 'com.android.support:appcompat-v7:27.1.0'
    compile 'com.android.support:design:27.1.0'
    compile 'com.android.support:recyclerview-v7:27.1.0'
    compile 'com.android.support:cardview-v7:27.1.0'
}
the following is the error details
