Android – Could not resolve all dependencies for configuration ‘:ZBarScannerActivityLib:classpath’

I am getting this error while executing gradle build from command line for ZBarScannerActivityLib library project.
Detail error message is as follow

*A problem occurred configuring project ':ZBarScannerActivityLib'.

Could not resolve all dependencies for configuration ':ZBarScannerActivityLib:classpath'.
Could not find com.android.tools.build:gradle:2.2.2.
Searched in the following locations:
https://repo1.maven.org/maven2/com/android/tools/build/gradle/2.2.2/gradle-2.2.2.pom
https://repo1.maven.org/maven2/com/android/tools/build/gradle/2.2.2/gradle-2.2.2.jar
Required by:
LDDAndroid:ZBarScannerActivityLib:unspecified*

build.gradle file for ZBarScannerActivityLib

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.2.2'
    }
}
apply plugin: 'android-library'

dependencies {
    compile fileTree(dir: 'libs', include: '*.jar')
}

android {
    compileSdkVersion 21
    buildToolsVersion "21.1.2"

    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            resources.srcDirs = ['src']
            aidl.srcDirs = ['src']
            renderscript.srcDirs = ['src']
            res.srcDirs = ['res']
            assets.srcDirs = ['assets']
            jniLibs.srcDir 'libs'
        }

        // Move the tests to tests/java, tests/res, etc...
        instrumentTest.setRoot('tests')

        // Move the build types to build-types/<type>
        // For instance, build-types/debug/java, build-types/debug/AndroidManifest.xml, ...
        // This moves them out of them default location under src/<type>/... which would
        // conflict with src/ being used by the main source set.
        // Adding new build types or product flavors should be accompanied
        // by a similar customization.
        debug.setRoot('build-types/debug')
        release.setRoot('build-types/release')
    }
}