Init exit menu item as hidden (#34482)

Initializes exit menu item as hidden for new users only by setting it as disabled during onboarding. Exit item will be shown as disabled in the customized menu and tapping it on the toggle will bring it back.

android/java/org/chromium/chrome/browser/firstrun/WelcomeOnboardingActivity.java

@@ -52,6 +52,7 @@ import org.chromium.base.ApplicationStatus;
 import org.chromium.base.ApplicationStatus.ActivityStateListener;
 import org.chromium.base.BravePreferenceKeys;
 import org.chromium.base.Log;
+import org.chromium.brave.browser.customize_menu.CustomizeBraveMenu;
 import org.chromium.build.annotations.NullMarked;
 import org.chromium.build.annotations.Nullable;
 import org.chromium.chrome.R;
@@ -234,6 +235,7 @@ public class WelcomeOnboardingActivity extends FirstRunActivityBase
             ChromeSharedPreferences.getInstance()
                     .writeBoolean(OnboardingPrefManager.SHOULD_SHOW_SEARCH_WIDGET_PROMO, true);
         }
+        CustomizeBraveMenu.initDefaultInvisibleItems(getResources());
         OnboardingPrefManager.getInstance().setP3aOnboardingShown(true);
 
         FirstRunStatus.setFirstRunFlowComplete(true);