aar文件在android studio中生成而不是apk

Question

当我构建apk时，它显示“Reveal in Folder”但生成“aar”文件而不是apk。它既不生成调试Apk也不生成签名Apk。在哪里我必须改变或我必须做什么才能使它成为apk？

我搜索了这个问题，但没有得到正确答案。

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

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    useLibrary 'org.apache.http.legacy'

    lintOptions {
        abortOnError false
    }

    defaultConfig {
        applicationId "com.justreliefdoctors"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        multiDexEnabled true
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
     packagingOptions {
        exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/DEPENDENCIES.txt'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/NOTICE.txt'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/LICENSE.txt'
    }
}
repositories {
    mavenCentral()
    maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
    maven { url "https://jitpack.io" }
    jcenter()
    maven { url 'https://github.com/leonardocardoso/mvn-repo/raw/master/maven-deploy' }
    maven { url 'https://maven.fabric.io/public' }
}

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'
    })
    // https://mvnrepository.com/artifact/org.apache.httpcomponents/httpmime
    compile group: 'org.apache.httpcomponents', name: 'httpmime', version: '4.3.5'
    // https://mvnrepository.com/artifact/org.apache.httpcomponents/httpcore
    compile group: 'org.apache.httpcomponents', name: 'httpcore', version: '4.3.2'


    compile project(':app')
    compile project(':framework')

    compile 'com.android.volley:volley:1.0.0'
    compile 'com.github.alamkanak:android-week-view:1.2.6'
    compile 'com.android.support:appcompat-v7:25.3.1'
    compile 'com.android.support:multidex:1.0.1'
    compile 'com.appeaser.sublimepickerlibrary:sublimepickerlibrary:2.1.1'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    compile 'com.android.support:support-v4:25.3.1'
    testCompile 'junit:junit:4.12'
}