Refactored Settings calls to removeUserOrSetEphemeral().

Test: atest com.android.car.user.CarUserServiceTest \
      android.car.apitest.CarDevicePolicyManagerTest#testRemoveUser_whenDisallowed
Bug: 170887769

Change-Id: If797ace64c0fa0262116f649212bbcb1d61e2046

src/com/android/settings/users/UserSettings.java

@@ -751,7 +751,8 @@ public class UserSettings extends SettingsPreferenceFragment
         }
         try {
             getContext().getSystemService(UserManager.class)
-                    .removeUserOrSetEphemeral(UserHandle.myUserId());
+                    .removeUserOrSetEphemeral(UserHandle.myUserId(),
+                            /* evenWhenDisallowed= */ false);
             ActivityManager.getService().switchUser(UserHandle.USER_SYSTEM);
         } catch (RemoteException re) {
             Log.e(TAG, "Unable to remove self user");