Log keys instead of notification.tostring()

Test: none
Fixes: 162014574
Change-Id: Iafb9f58c95e5ad8cc9862eb92cf06a897086f71d
diff --git a/src/android/ext/services/notification/Assistant.java b/src/android/ext/services/notification/Assistant.java
index dd5d1fd..721558b 100644
--- a/src/android/ext/services/notification/Assistant.java
+++ b/src/android/ext/services/notification/Assistant.java
@@ -187,7 +187,7 @@
             mLiveNotifications.remove(sbn.getKey());
 
         } catch (Throwable e) {
-            Log.e(TAG, "Error occurred processing removal of " + sbn, e);
+            Log.e(TAG, "Error occurred processing removal of " + sbn.getKey(), e);
         }
     }