OpenCv:Face-detection = java.lang.UnsatisfiedLinkError: Couldn't load detection_based_tracker from loader dalvik.system.PathClassLoader

edit

my build.gradle :

android { compileSdkVersion 25 buildToolsVersion "25.0.3" defaultConfig { applicationId "com.example.sspl.myopencv" minSdkVersion 19 targetSdkVersion 25 versionCode 1 versionName "1.0" testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

    ndk {
        moduleName "detection_based_tracker"
    }
}

sourceSets.main {
    jniLibs.srcDir 'src/main/libs'
    jni.srcDirs = []
}

buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}

}

dependencies { compile project(':openCVLibrary330') 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:appcompat-v7:25.3.1' // compile 'com.android.support.constraint:constraint-layout:1.0.2' testCompile 'junit:junit:4.12' }