Update logging to help debug b/200572078

The class name logged in a repro of b/200572078 was insufficient after updated logs. Added more logging to get a pointer and stack trace when callbacks are added.

Test: ran launcher and checked logs
Bug: 200572078
Change-Id: I01bf98f488204311415a3946d66d99f656387cc4
diff --git a/src/com/android/launcher3/LauncherModel.java b/src/com/android/launcher3/LauncherModel.java
index f38f662..ee6f51e 100644
--- a/src/com/android/launcher3/LauncherModel.java
+++ b/src/com/android/launcher3/LauncherModel.java
@@ -60,6 +60,7 @@
 import com.android.launcher3.pm.PackageInstallInfo;
 import com.android.launcher3.pm.UserCache;
 import com.android.launcher3.shortcuts.ShortcutRequest;
+import com.android.launcher3.testing.TestProtocol;
 import com.android.launcher3.util.IntSet;
 import com.android.launcher3.util.ItemInfoMatcher;
 import com.android.launcher3.util.PackageUserKey;
@@ -346,6 +347,12 @@
     public void addCallbacks(Callbacks callbacks) {
         Preconditions.assertUIThread();
         synchronized (mCallbacksList) {
+            if (TestProtocol.sDebugTracing) {
+                Log.d(TestProtocol.NULL_INT_SET, "addCallbacks pointer: "
+                        + callbacks
+                        + ", name: "
+                        + callbacks.getClass().getName(), new Exception());
+            }
             mCallbacksList.add(callbacks);
         }
     }