Revert "[iOS] Reenable disabled test"

This reverts commit 32c3c769.

Reason for revert:

ReadingListTestCase/testSwipeDownDismiss is failing again. 
Oct 21 2020 https://ci.chromium.org/ui/p/chrome/builders/ci/ios14-sdk-simulator/510/overview
Dec 11 2020 https://ci.chromium.org/ui/p/chrome/builders/ci/ios14-sdk-simulator/712/overview


Original change's description:
> [iOS] Reenable disabled test
>
> It seems to pass now.
>
> Fixed: 1129589
> Change-Id: Id2fd68a6e3f860f593871c4a223bc0a8f034cefd
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2460825
> Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
> Commit-Queue: Gauthier Ambard <gambard@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#815142}

TBR=olivierrobin@chromium.org,gambard@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: Id32622132efa0535dff419886cf859b18594b074
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2587697Reviewed-by: edchin <edchin@chromium.org>
Commit-Queue: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836351}

ios/chrome/browser/ui/reading_list/reading_list_egtest.mm

@@ -1026,6 +1026,10 @@ void AssertIsShowingDistillablePage(bool online, const GURL& distillable_url) {
 
 // Tests that the VC can be dismissed by swiping down.
 - (void)testSwipeDownDismiss {
+  // TODO(crbug.com/1129589): Test disabled on iOS14 iPhones.
+  if (base::ios::IsRunningOnIOS14OrLater() && ![ChromeEarlGrey isIPadIdiom]) {
+    EARL_GREY_TEST_DISABLED(@"Fails on iOS14 iPhones.");
+  }
   if (!base::ios::IsRunningOnOrLater(13, 0, 0)) {
     EARL_GREY_TEST_SKIPPED(@"Test disabled on iOS 12 and lower.");
   }