[iOS] Search for payment methods autofill setting

On small devices, the "Payment Methods" row in settings may require
scrolling the settings table in order to make it visible. Add a scroll
down search action to scroll the settings table until the row is found.

Change-Id: If4ff25908e117521236c01eca1d61ca8e61ba256
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2412249
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Auto-Submit: Mike Dougherty <michaeldo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807081}

ios/chrome/browser/ui/settings/autofill/autofill_credit_card_settings_egtest.mm

@@ -93,9 +93,11 @@ id<GREYMatcher> BottomToolbar() {
 // Helper to open the settings page for Autofill credit cards.
 - (void)openCreditCardsSettings {
   [ChromeEarlGreyUI openSettingsMenu];
-  [[EarlGrey selectElementWithMatcher:ButtonWithAccessibilityLabel(
-                                          l10n_util::GetNSString(
-                                              IDS_AUTOFILL_PAYMENT_METHODS))]
+  [[[EarlGrey selectElementWithMatcher:ButtonWithAccessibilityLabel(
+                                           l10n_util::GetNSString(
+                                               IDS_AUTOFILL_PAYMENT_METHODS))]
+         usingSearchAction:grey_scrollInDirection(kGREYDirectionDown, 200)
+      onElementWithMatcher:chrome_test_util::SettingsCollectionView()]
       performAction:grey_tap()];
 }