Allow enable DBG/VDBG without having to rebuild the module.

Check out #isLoggable from frameworks/base/core/java/android/util/Log.java to
learn how to enable the log.

Bug: 329552689
Change-Id: I86ce0dae947cf56da069dfe3145ef074de11217e
Test: TH
diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index 544ba01..9e0c970 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -137,8 +137,8 @@
     private static final MacAddress NULL_MAC_ADDRESS = MacAddress.fromString("00:00:00:00:00:00");
 
     private static final String TAG = "IpServer";
-    private static final boolean DBG = false;
-    private static final boolean VDBG = false;
+    private static final boolean DBG = Log.isLoggable(TAG, Log.DEBUG);
+    private static final boolean VDBG = Log.isLoggable(TAG, Log.VERBOSE);
     private static final Class[] sMessageClasses = {
             IpServer.class
     };
diff --git a/Tethering/src/com/android/networkstack/tethering/Tethering.java b/Tethering/src/com/android/networkstack/tethering/Tethering.java
index 873961a..235e359 100644
--- a/Tethering/src/com/android/networkstack/tethering/Tethering.java
+++ b/Tethering/src/com/android/networkstack/tethering/Tethering.java
@@ -173,8 +173,8 @@
 public class Tethering {
 
     private static final String TAG = Tethering.class.getSimpleName();
-    private static final boolean DBG = false;
-    private static final boolean VDBG = false;
+    private static final boolean DBG = Log.isLoggable(TAG, Log.DEBUG);
+    private static final boolean VDBG = Log.isLoggable(TAG, Log.VERBOSE);
 
     private static final Class[] sMessageClasses = {
             Tethering.class, TetherMainSM.class, IpServer.class