Remove temp user creation activity

Supervised user creation required a temporary activity until it could
be properly implemented.

Bug: 209659998
Test: Add supervised user
Change-Id: I3aae23a5782f8c58ed137e0fc96dd41bdebe2784

packages/SystemUI/src/com/android/systemui/statusbar/policy/UserSwitcherController.java

@@ -584,13 +584,6 @@ public class UserSwitcherController implements Dumpable {
                 .setPackage(mCreateSupervisedUserPackage)
                 .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 
-        // TODO(b/209659998): [to-be-removed] fallback activity for supervised user creation.
-        if (mContext.getPackageManager().resolveActivity(intent, 0) == null) {
-            intent.setPackage(null)
-                    .setClassName("com.android.settings",
-                        "com.android.settings.users.AddSupervisedUserActivity");
-        }
-
         mContext.startActivity(intent);
     }