修改app.gradle文件：

android {
    ....................................................

    //配置keystore签名
    signingConfigs {
        release {
            storeFile file("./cert/android.keystore")
            storePassword "123456"
            keyAlias "android"
            keyPassword "123456"
        }
    }

    buildTypes {
        debug {
            debuggable true
            signingConfig signingConfigs.release
        }
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            signingConfig signingConfigs.release
        }
    }
}