[iOS] Disable testCutInPreedit

The test is consistently failing on the first run.

TBR=stkhapugin@chromium.org

Bug: 1049603
Change-Id: I8794ea5bed6d44b116b97336dc18b04b7dd8364d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2042099Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738979}

ios/chrome/browser/ui/omnibox/omnibox_egtest.mm

@@ -369,7 +369,8 @@ id<GREYMatcher> SearchCopiedTextButton() {
 // Focus the omnibox and hit "cmd+X". This should remove all text from the
 // omnibox and put it in the clipboard. This had been broken before because of
 // the preedit state complexity. Paste to verify that the URL was indeed copied.
-- (void)testCutInPreedit {
+// TODO(crbug.com/1049603): Re-enable this test.
+- (void)DISABLED_testCutInPreedit {
   [self openPage1];
 
   [ChromeEarlGreyUI focusOmnibox];