我已经搜索过以前的帖子，但找不到我问题的答案。这里是我的代码，来自我的build.gradle文件。
错误：评估项目'：app'时发生问题。
无法获取类型为org.gradle.api.internal.artifacts.dsl.dependencies.DefaultDependencyHandler的对象的未知属性“实现”。

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
android {
    compileSdkVersion 29
    defaultConfig {
        applicationId "com.loganwiley.findmyphone"
        minSdkVersion 17
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
        compileKotlin {
            kotlinOptions.suppressWarnings = true
        }

        compileKotlin {
            kotlinOptions {
                suppressWarnings = true
            }
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'+
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'+
    implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'+
    implementation 'com.google.firebase:firebase-auth:10.2.4'+
    implementation 'com.google.firebase:firebase-database:10.2.4'+
    implementation 'com.google.android.gms:play-services-maps:10.2.4'+
    implementation 'com.android.support:design:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.2'+
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'+
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}
repositories {
    mavenCentral()
}

apply plugin: 'com.google.gms.google-services'