How to use App indexing Api's by extending a class with Prime31 's UnityPlayerActivity ?

Hi , Currently i am developing an App indexing Auto complete feature in to my game , for that i created a demo Unity project created the plugin for app indexing , and while creating the plugin i extended my class with UnityPlayerActivity which is came from il2cpp's classes.jar , but in our game we used Prime 31 plugins , prime31 documentation says that,

"Any other third party (non prime[31]) plugins that do override the main Unity Activity will not work in the same game. In order to facilate compatibility for all Unity plugins we developed an Activity sharing system that is freely available for anyone (including other plugin vendors) to use."

so i included prime31UnityActivity.jar in libs directory of Android but i am not able to find instance of the extended class , i am getting a syntax error at keyword this.

public static void onCreate(Bundle savedInstanceState) {

     Log.d("onCreate","in oncreate method");

     //super.onCreate(savedInstanceState);

     mClient = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();

}