Mark testBrowsingPostEntryWithKeyboard as FLAKY_.

ios/chrome/browser/web/browsing_egtest.mm

Index: ios/chrome/browser/web/browsing_egtest.mm
diff --git a/ios/chrome/browser/web/browsing_egtest.mm b/ios/chrome/browser/web/browsing_egtest.mm
index c8a93952cbdb97bc7634415de8aecd3ecd685a12..ffa0d968276afd6399a14f14d84ff4d66fef895b 100644
--- a/ios/chrome/browser/web/browsing_egtest.mm
+++ b/ios/chrome/browser/web/browsing_egtest.mm
@@ -632,7 +632,8 @@ id<GREYMatcher> GoButtonMatcher() {
 // Tests that submitting a POST-based form by tapping the 'Go' button on the
 // keyboard navigates to the correct URL and the back button works as expected
 // afterwards.
-- (void)testBrowsingPostEntryWithKeyboard {
+// TODO(crbug.com/704618): Re-enable this test when the flake is fixed.
+- (void)FLAKY_testBrowsingPostEntryWithKeyboard {
   // Create map of canned responses and set up the test HTML server.
   std::map<GURL, std::string> responses;
   const GURL URL =