Remove "Add users from lock screen" from secondary users

Fixes: 124885010
Test: Robolectric, manual
Change-Id: I1c940fda2fa5f3da39c19bd119ac483024f5a83b

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

@@ -38,10 +38,14 @@ public class AddUserWhenLockedPreferenceController extends TogglePreferenceContr
         mUserCaps.updateAddUserCapabilities(mContext);
         final RestrictedSwitchPreference restrictedSwitchPreference =
                 (RestrictedSwitchPreference) preference;
+        if (!isAvailable()) {
+            restrictedSwitchPreference.setVisible(false);
+        } else {
             restrictedSwitchPreference.setDisabledByAdmin(
                     mUserCaps.disallowAddUser() ? mUserCaps.getEnforcedAdmin() : null);
             restrictedSwitchPreference.setVisible(mUserCaps.mUserSwitcherEnabled);
         }
+    }
 
     @Override
     public int getAvailabilityStatus() {

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

@@ -289,10 +289,8 @@ public class UserSettings extends SettingsPreferenceFragment
         }
         final PreferenceScreen screen = getPreferenceScreen();
 
-        if (mAddUserWhenLockedPreferenceController.isAvailable()) {
         mAddUserWhenLockedPreferenceController.updateState(screen.findPreference(
                 mAddUserWhenLockedPreferenceController.getPreferenceKey()));
-        }
 
         if (mShouldUpdateUserList) {
             updateUI();

tests/robotests/src/com/android/settings/users/AddUserWhenLockedPreferenceControllerTest.java

@@ -30,6 +30,7 @@ import androidx.preference.PreferenceScreen;
 import com.android.settings.testutils.shadow.ShadowUserManager;
 import com.android.settingslib.RestrictedSwitchPreference;
 
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -57,6 +58,12 @@ public class AddUserWhenLockedPreferenceControllerTest {
         mContext = RuntimeEnvironment.application;
         mUserManager = ShadowUserManager.getShadow();
         mController = new AddUserWhenLockedPreferenceController(mContext, "fake_key");
+        mUserManager.setSupportsMultipleUsers(true);
+    }
+
+    @After
+    public void tearDown() {
+        ShadowUserManager.reset();
     }
 
     @Test
@@ -71,6 +78,30 @@ public class AddUserWhenLockedPreferenceControllerTest {
         verify(preference).setVisible(false);
     }
 
+    @Test
+    public void updateState_NotAdmin_shouldNotDisplayPreference() {
+        mUserManager.setIsAdminUser(false);
+        final RestrictedSwitchPreference preference = mock(RestrictedSwitchPreference.class);
+
+        mController.updateState(preference);
+
+        verify(preference).setVisible(false);
+    }
+
+    @Test
+    public void updateState_Admin_shouldDisplayPreference() {
+        mUserManager.setIsAdminUser(true);
+        mUserManager.setUserSwitcherEnabled(true);
+        mUserManager.setSupportsMultipleUsers(true);
+        final AddUserWhenLockedPreferenceController controller =
+                new AddUserWhenLockedPreferenceController(mContext, "fake_key");
+        final RestrictedSwitchPreference preference = mock(RestrictedSwitchPreference.class);
+
+        controller.updateState(preference);
+
+        verify(preference).setVisible(true);
+    }
+
     @Test
     public void updateState_preferenceSetCheckedWhenSettingIsOn() {
         final RestrictedSwitchPreference preference = mock(RestrictedSwitchPreference.class);