[iOS] Disable flaky testRestoreToWarningPagePreservesHistory

This disables
SafeBrowsingTestCase/testRestoreToWarningPagePreservesHistory
since it is flaky.

Bug: 1106498
Change-Id: I0953c8c0f2c36ea01a7e1f0ff738db6c842df94f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2308867
Auto-Submit: Ali Juma <ajuma@chromium.org>
Commit-Queue: Eugene But <eugenebut@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#790448}

ios/chrome/browser/safe_browsing/safe_browsing_egtest.mm

@@ -428,7 +428,8 @@ const char kMalwareWarningDetails[] =
 
 // Tests that performing session restoration to a Safe Browsing warning page
 // preserves navigation history.
-- (void)testRestoreToWarningPagePreservesHistory {
+// TODO(crbug.com/1106498): Re-enable this test after fixing flakiness.
+- (void)DISABLED_testRestoreToWarningPagePreservesHistory {
   // Build up navigation history that consists of a safe URL, a warning page,
   // and another safe URL.
   [ChromeEarlGrey loadURL:_safeURL1];