Cannot find ScriptC_saturation in BasicRenderScript example

I imported the Basic RenderScript Sample project from Android Samples .

Android Studio shows

error: cannot find symbol class ScriptC_saturation

This is an import.

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.support.v8.renderscript.*;

I searched, but can not find much about it. What am I missing?

[EDIT] This is my file build.gradle.

buildscript {
    repositories {
        mavenCentral()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:0.8.+'
    }
}

apply plugin: 'android'

dependencies {
    // Add the support lib that is appropriate for SDK 8
    compile "com.android.support:support-v4:19.0.+"
    compile "com.android.support:gridlayout-v7:19.0.+"
    compile files('renderscript-v8.jar')
}

// The sample build uses multiple directories to
// keep boilerplate and common code separate from
// the main sample code.
List<String> dirs = [
    'main',     // main sample code; look here for the interesting stuff.
    'common',   // components that are reused by multiple samples
    'template'] // boilerplate code that is generated by the sample template process

android {
    compileSdkVersion 19
    buildToolsVersion "19.0.1"

    sourceSets {
        main {
            dirs.each { dir ->
                java.srcDirs "src/${dir}/java"
                res.srcDirs "src/${dir}/res"
            }
        }
        instrumentTest.setRoot('tests')
        instrumentTest.java.srcDirs = ['tests/src']

        defaultConfig {
            renderscriptTargetApi 18
            renderscriptSupportMode true
        }
    }
}