Fix visibility of settings on channel page

Properly hide fields if the parent app or group
is blocked. This is needed because apps can link
directly to this screen.

Test: atest
Fixes: 130184191
Change-Id: I8c39410574940615fbb607a201e20e480ec02d87

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

@@ -50,12 +50,18 @@ public class ImportancePreferenceController extends NotificationPreferenceContro
         if (mAppRow == null) {
             return false;
         }
+        if (mAppRow.banned) {
+            return false;
+        }
         if (mChannel == null) {
             return false;
         }
         if (isDefaultChannel()) {
             return false;
         }
+        if (mChannelGroup != null && mChannelGroup.isBlocked()) {
+            return false;
+        }
         return true;
     }