[Notif] Allow locking importance on notification

Currently locking  only works on channel - this CL allows doing
so on the overarching notification too. Added locking field in
appropriate places in record and surfaced it to other bits via
the RankingHelper.

Test: Visually, reproduced organically (+ deleting /data/ files)
Fixes: 77775657
Change-Id: Ie46093921dd6c1ae3533ded7b87faaa475a631e4
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationInfo.java b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationInfo.java
index 81dd9e8..8062064 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationInfo.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationInfo.java
@@ -523,7 +523,7 @@
                 } else {
                     // For notifications with more than one channel, update notification enabled
                     // state. If the importance was lowered, we disable notifications.
-                    mINotificationManager.setNotificationsEnabledForPackage(
+                    mINotificationManager.setNotificationsEnabledWithImportanceLockForPackage(
                             mPackageName, mAppUid, mNewImportance >= mCurrentImportance);
                 }
             } catch (RemoteException e) {