Don't hide approved NLSes in Settings

Note that an NLS that shouldn't be approvable (because its name is too long) but was already approved (either before the max length check was introduced, or through other means) will disappear from the list if the user revokes its access. This might be somewhat confusing, but since this is a very-edge case already it's fine.

Bug: 282932362
Test: manual
Change-Id: I4c9faea68e6d16b1a4ec7f472b5433cac1704c06

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

@@ -143,6 +143,9 @@ public class NotificationBackend {
 
     static public CharSequence getDeviceList(ICompanionDeviceManager cdm, LocalBluetoothManager lbm,
             String pkg, int userId) {
+        if (cdm == null) {
+            return "";
+        }
         boolean multiple = false;
         StringBuilder sb = new StringBuilder();