[Sheriff] Disable flaky test, LocationBarSteadyStateTestCase/testCopyPaste.

Failure reason:
Exception: NoMatchingElementException

TBR=stkhapugin@chromium.org

Bug: 1056700
Change-Id: I2ee0b6871d2ef725316c158f0cbe2167315b969b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2078434Reviewed-by: Katie Dektar <katie@chromium.org>
Commit-Queue: Katie Dektar <katie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#745115}

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

@@ -226,7 +226,8 @@ id<GREYMatcher> SearchCopiedTextButton() {
   }
 }
 
-- (void)testCopyPaste {
+// Test is flaky: crbug.com/1056700.
+- (void)DISABLED_testCopyPaste {
   [self openPage1];
 
   // Long pressing should allow copying.