[MS60] Remove TrafficStats.TAG_SYSTEM_APP dependency

Replace with system Api.

Test: TH
Bug: 204830222
Change-Id: If2ef0dbb058c4360f046b1c16fdf467594249b03

core/java/android/net/PrivateDnsConnectivityChecker.java

@@ -44,7 +44,7 @@ public class PrivateDnsConnectivityChecker {
      */
     public static boolean canConnectToPrivateDnsServer(@NonNull String hostname) {
         final SocketFactory factory = SSLSocketFactory.getDefault();
-        TrafficStats.setThreadStatsTag(TrafficStats.TAG_SYSTEM_APP);
+        TrafficStats.setThreadStatsTagApp();
 
         try (SSLSocket socket = (SSLSocket) factory.createSocket()) {
             socket.setSoTimeout(CONNECTION_TIMEOUT_MS);