Remove a comment from ConnectivityService

This comment is not true anymore since NetworkMonitor is not only
verifying the default network but also verifying VPN when private
DNS is enabled.

Test: Build pass.
Change-Id: Ib975aa28c84b9974a73d1baca9d5185c01b71217

services/core/java/com/android/server/ConnectivityService.java

@@ -5854,7 +5854,6 @@ public class ConnectivityService extends IConnectivityManager.Stub
     @GuardedBy("mBlockedAppUids")
     private final HashSet<Integer> mBlockedAppUids = new HashSet<>();
 
-    // Note: if mDefaultRequest is changed, NetworkMonitor needs to be updated.
     @NonNull
     private final NetworkRequest mDefaultRequest;
     // The NetworkAgentInfo currently satisfying the default request, if any.