Fix DNS issues: Add 4 DoH servers with fallback, remove ineffective DNSSetter

- Remove DNSSetter.java (System.setProperty doesn't affect Android DNS)
- Update NetworkUtils with 4 DNS over HTTPS providers:
  * Google DNS (8.8.8.8) - Primary
  * Cloudflare (1.1.1.1) - Secondary
  * AdGuard (94.140.14.14) - Tertiary
  * Quad9 (9.9.9.9) - Quaternary
- Update DeviceRegistry to use NetworkUtils client
- Update UpdateManager to use NetworkUtils client
- Remove DNSSetter call from PlayerActivity

This ensures the app works even when ISPs block specific DNS servers.

app/src/main/java/com/streamplayer/PlayerActivity.java

@@ -87,7 +87,7 @@ public class PlayerActivity extends AppCompatActivity {
         initViews();
         channelLabel.setText(channelName);
 
-        DNSSetter.configureDNSToGoogle(this);
+        // DNS over HTTPS ya está configurado en NetworkUtils
         loadChannel();
     }