AF passwords settings: Start activity as new task.

Settings app has a new 2-pane layout for larger screens. Activities that
belong to other apps must now be started as a new task.

Fix: 197702325
Test: manual
Change-Id: Iaf800b7f9e6bf5d925047fed49d848f4d3973df7

src/com/android/settings/applications/autofill/PasswordsPreferenceController.java

@@ -16,6 +16,7 @@
 
 package com.android.settings.applications.autofill;
 
+import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
 import static android.service.autofill.AutofillService.EXTRA_RESULT;
 
 import static androidx.lifecycle.Lifecycle.Event.ON_CREATE;
@@ -133,7 +134,8 @@ public class PasswordsPreferenceController extends BasePreferenceController
                         new Intent(Intent.ACTION_MAIN)
                                 .setClassName(
                                         serviceInfo.packageName,
-                                        service.getPasswordsActivity());
+                                        service.getPasswordsActivity())
+                                .setFlags(FLAG_ACTIVITY_NEW_TASK);
                 prefContext.startActivityAsUser(intent, UserHandle.of(user));
                 return true;
             });