Disable JavaScriptDialogTestCase testShowJavaScriptAfterNewTabAnimation EG Test

Test has been flaky on iOS13 simulators since it was enabled in:
https://chromium-review.googlesource.com/c/chromium/src/+/1804214

TBR=michaeldo@chromium.org

Change-Id: I3f76bd737d3f7c42e544489c24b6abcb54346ee4
Bug: 1007986
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1823892Reviewed-by: Sebastien Lalancette <seblalancette@chromium.org>
Auto-Submit: Sebastien Lalancette <seblalancette@chromium.org>
Commit-Queue: Sebastien Lalancette <seblalancette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699797}

ios/chrome/browser/ui/dialogs/javascript_dialog_egtest.mm

@@ -575,6 +575,11 @@ void TapSuppressDialogsButton() {
 
 // Tests that an alert is presented after a new tab animation is finished.
 - (void)testShowJavaScriptAfterNewTabAnimation {
+  // TODO(crbug.com/1007986) Test flaky on iOS13.
+  if (@available(iOS 13, *)) {
+    EARL_GREY_TEST_DISABLED(@"Test disabled on iOS13.");
+  }
+
   // Load the test page with a link to kOnLoadAlertURL and long tap on the link.
   [self loadPageWithLink];