NoMan: Don't unbind system listeners

Listeners registered via INotificationMananger.registerListener()
must not be unbound by NoMan because it won't be able to re-bind
them later.

Bug: 15131411
Change-Id: Ic5088252c86e7c32c522ba1606f123cefde3720d
diff --git a/services/core/java/com/android/server/notification/ManagedServices.java b/services/core/java/com/android/server/notification/ManagedServices.java
index b94ea62..1b1fc8b 100644
--- a/services/core/java/com/android/server/notification/ManagedServices.java
+++ b/services/core/java/com/android/server/notification/ManagedServices.java
@@ -259,13 +259,17 @@
                     userIds[i]));
         }
 
-        ManagedServiceInfo[] toRemove = new ManagedServiceInfo[mServices.size()];
+        ArrayList<ManagedServiceInfo> toRemove = new ArrayList<ManagedServiceInfo>();
         final SparseArray<ArrayList<ComponentName>> toAdd
                 = new SparseArray<ArrayList<ComponentName>>();
 
         synchronized (mMutex) {
-            // unbind and remove all existing services
-            toRemove = mServices.toArray(toRemove);
+            // Unbind automatically bound services, retain system services.
+            for (ManagedServiceInfo service : mServices) {
+                if (!service.isSystem) {
+                    toRemove.add(service);
+                }
+            }
 
             final ArraySet<ComponentName> newEnabled = new ArraySet<ComponentName>();
             final ArraySet<String> newPackages = new ArraySet<String>();