即使在添加所有庫後仍未找到類「android.support.v4.content.ContextCompat」

當我將targetSDK更改爲大於22時，編譯器不允許直接使用權限。權限必須由用戶來提供，我不得不使用下面的代碼：即使在添加所有庫後仍未找到類「android.support.v4.content.ContextCompat」

if(ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)!= PackageManager.PERMISSION_GRANTED) { 

     ActivityCompat.requestPermissions(this, 
       new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 
       MY_PERMISSSIONS_REQUEST_FINE_LOCATION); 

}

但我不斷收到以下錯誤

Didn't find class "android.support.v4.content.ContextCompat"

我添加了所有必需的文件ContextCompat和ActivityCompat但我每次都會收到這個錯誤。這是我的build.gradle

[編輯]添加整個文件的gradle

apply plugin: 'com.android.library' 

    android { 
     compileSdkVersion 25 
     buildToolsVersion "25.0.2" 

     defaultConfig { 
      minSdkVersion 15 
      targetSdkVersion 25 
      versionCode 1 
      versionName "1.0" 

      testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner" 

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

    dependencies { 
     compile fileTree(include: ['*.jar'], dir: 'libs') 
     compile 'com.android.support:appcompat-v7:25.2.0' 
     compile files('libs/classes.jar') 
     compile 'com.android.support:support-v4:25.2.0' 
    } 

    //task to delete the old jar 
    task deleteOldJar(type: Delete) { 
     delete '/Users/kushagragupta/Desktop/Kushagra/STURFEE/Sturfee.Unity.Mobile.IMUGPSTest/Assets/AndroidPlugin.jar' 
    } 

    //task to export contents as jar 
    task exportJar(type: Copy) { 
     from('build/intermediates/bundles/release/') 
     into('/Users/kushagragupta/Desktop/Kushagra/STURFEE/Sturfee.Unity.Mobile.IMUGPSTest/Assets/') 
     include('classes.jar') 
     ///Rename the jar 
     rename('classes.jar', 'AndroidPlugin.jar') 
    } 

    exportJar.dependsOn(deleteOldJar, build)

我可以從字面上看這些庫Android Studio中