Fixes stop promotions for notifications

Resolves brave#13021

Auditors:

Test Plan:

app/browser/api/ledgerNotifications.js

@@ -364,7 +364,8 @@ const showPromotionNotification = (state) => {
     (
       getSetting(settings.PAYMENTS_ENABLED) &&
       !getSetting(settings.PAYMENTS_NOTIFICATIONS)
-    )
+    ) ||
+    !getSetting(settings.PAYMENTS_ALLOW_PROMOTIONS)
   ) {
     return
   }

test/unit/app/browser/api/ledgerNotificationsTest.js

@@ -19,6 +19,7 @@ describe('ledgerNotifications unit test', function () {
   let paymentsNotifications
   let paymentsMinVisitTime = 5000
   let paymentsContributionAmount = 25
+  let paymentsAllowPromotions = true
 
   const defaultAppState = Immutable.fromJS({
     ledger: {},
@@ -49,6 +50,8 @@ describe('ledgerNotifications unit test', function () {
             return paymentsMinVisitTime
           case settings.PAYMENTS_CONTRIBUTION_AMOUNT:
             return paymentsContributionAmount
+          case settings.PAYMENTS_ALLOW_PROMOTIONS:
+            return paymentsAllowPromotions
         }
         return false
       }
@@ -591,6 +594,13 @@ describe('ledgerNotifications unit test', function () {
       assert(showNotificationSpy.calledOnce)
     })
 
+    it('promotions are disabled, notification is not shown', function () {
+      paymentsAllowPromotions = false
+      ledgerNotificationsApi.showPromotionNotification(state)
+      assert(showNotificationSpy.notCalled)
+      paymentsAllowPromotions = true
+    })
+
     it('notification is shown', function () {
       ledgerNotificationsApi.showPromotionNotification(state)
       assert(showNotificationSpy.calledOnce)