Don't show back arrow in Security when in split mode.

Test: manual
Bug: 224427042
Change-Id: I0b0daa3981c56ba99bebda2cd34a51f3877f37a6

src/com/android/settings/security/TopLevelSecurityEntryPreferenceController.java

@@ -58,6 +58,7 @@ public class TopLevelSecurityEntryPreferenceController extends BasePreferenceCon
                 new SubSettingLauncher(mContext)
                         .setDestination(alternativeFragmentClassname)
                         .setSourceMetricsCategory(getMetricsCategory())
+                        .setIsSecondLayerPage(true)
                         .launch();
                 return true;
             }