Import HexDump class from frameworks/libs/net.

Test: atest NetworkStackIntegrationTests
Change-Id: Ib72682ec127bc33972d2214f39eb11f88a21ab1f
diff --git a/src/android/net/ip/IpClientLinkObserver.java b/src/android/net/ip/IpClientLinkObserver.java
index a9bdebc..0771bff 100644
--- a/src/android/net/ip/IpClientLinkObserver.java
+++ b/src/android/net/ip/IpClientLinkObserver.java
@@ -45,7 +45,7 @@
 import androidx.annotation.Nullable;
 
 import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.util.HexDump;
+import com.android.net.module.util.HexDump;
 import com.android.net.module.util.InterfaceParams;
 import com.android.net.module.util.SharedLog;
 import com.android.net.module.util.ip.NetlinkMonitor;