I was trying to implement the d-pad control functionality in my android tv app but it is not working properly

Question

This is my andexoplayer activity file and i am using the exoplayer library to play videos in android tv app.I was trying to implement the d-pad control functionality in my android tv app but it is not working properly.

package com.amigofx.ssnews;

import android.os.Bundle;
import android.support.v4.media.session.MediaControllerCompat;
import android.view.KeyEvent;
import android.view.View;
import android.view.WindowManager;

import com.potyvideo.library.AndExoPlayerView;

import androidx.appcompat.app.AppCompatActivity;

public class AndexoPlayer extends AppCompatActivity {
    private AndExoPlayerView andExoPlayerView;
    String video_url = "https://5dd3981940faa.streamlock.net:443/snewsnpt/snewsnpt/playlist.m3u8";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.andexoplayer);

        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); // keeps screen on

        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN); // enable full screen

        andExoPlayerView = (AndExoPlayerView) findViewById(R.id.andExoPlayerView);
        andExoPlayerView.setSource(video_url);
    }

    @Override
    protected void onStop() {
        super.onStop();
        andExoPlayerView.stopPlayer();
    }
}