Extract the not-strictly-modes-related parts of ZenModesBackend

So that when it's moved to SettingsLib, it doesn't need to carry that baggage.

Bug: 346519570
Test: atest com.android.settings.notification.modes
Flag: android.app.modes_ui
Change-Id: I7911a521d96f5dbac2c2395171d324b7b54b8b07

src/com/android/settings/notification/NotificationBackend.java

@@ -357,19 +357,6 @@ public class NotificationBackend {
         }
     }
 
-    /**
-     * Returns all of a user's packages that have at least one channel that will bypass DND
-     */
-    public List<String> getPackagesBypassingDnd(int userId,
-            boolean includeConversationChannels) {
-        try {
-            return sINM.getPackagesBypassingDnd(userId, includeConversationChannels);
-        } catch (Exception e) {
-            Log.w(TAG, "Error calling NoMan", e);
-            return new ArrayList<>();
-        }
-    }
-
     public void updateChannel(String pkg, int uid, NotificationChannel channel) {
         try {
             sINM.updateNotificationChannelForPackage(pkg, uid, channel);