Always call back when printer changes

Otherwise it can happen that we swallow previous printer updates and
never end up getting a valid on-printers-updated call.

Fixes: 156222510
Test: atest PrinterDiscoverySessionLifecycleTest
Change-Id: Idab7399a6ab41ba9051cfcbbeebf4c45d6bfc053

packages/PrintSpooler/src/com/android/printspooler/ui/FusedPrintersProvider.java

@@ -231,11 +231,6 @@ public final class FusedPrintersProvider extends Loader<List<PrinterInfo>>
         // Add the new printers, i.e. what is left.
         printers.addAll(discoveredPrinters.values());
 
-        // Do nothing if the printer list is not changed.
-        if (Objects.equals(mPrinters, printers)) {
-            return;
-        }
-
         // Update the list of printers.
         mPrinters.clear();
         mPrinters.addAll(printers);