Only cancel notification if update isn't installed

* Even if the package is removed on A/B devices
  we still want to show the reboot notification

Change-Id: I980d36766a1427874b65b11674a8f0ae4ce1db88
diff --git a/src/org/lineageos/updater/controller/UpdaterService.java b/src/org/lineageos/updater/controller/UpdaterService.java
index 61db18a..3371618 100644
--- a/src/org/lineageos/updater/controller/UpdaterService.java
+++ b/src/org/lineageos/updater/controller/UpdaterService.java
@@ -126,7 +126,10 @@
                     if (extras != null && downloadId.equals(
                             extras.getString(UpdaterController.EXTRA_DOWNLOAD_ID))) {
                         mNotificationBuilder.setExtras(null);
-                        mNotificationManager.cancel(NOTIFICATION_ID);
+                        UpdateInfo update = mUpdaterController.getUpdate(downloadId);
+                        if (update.getStatus() != UpdateStatus.INSTALLED) {
+                            mNotificationManager.cancel(NOTIFICATION_ID);
+                        }
                     }
                 }
             }