Disable a flaky LoginUIKeyboardTestWithUsersAndOwner.CheckPODScreenKeyboard

It has been flaky on the chrome os bots since
https://crrev.com/c/2215650 landed. As this change has a WebUI
Mojo pipe, the order in which WebUI's Send API is called has
changed, and the test is failed when 'hideOobeDialog' is called
through WebUI's Send and IME's state is updated to show the
sign-in screen before the test's result is checked.

Bug: 1104861
Change-Id: Iccaf905dd63f4e1e22b8ca399079e1e6a3cee08f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2297207
Commit-Queue: Miyoung Shin <myid.shin@igalia.com>
Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#788558}

chrome/browser/chromeos/login/login_ui_keyboard_browsertest.cc

@@ -295,8 +295,10 @@ IN_PROC_BROWSER_TEST_F(LoginUIKeyboardTestWithUsersAndOwner,
   StartupUtils::MarkOobeCompleted();
 }
 
+// TODO(crbug.com/1104861): Test has been flaky since
+// https://crrev.com/c/2215650 landed.
 IN_PROC_BROWSER_TEST_F(LoginUIKeyboardTestWithUsersAndOwner,
-                       CheckPODScreenKeyboard) {
+                       DISABLED_CheckPODScreenKeyboard) {
   EXPECT_EQ(3, ash::LoginScreenTestApi::GetUsersCount());
 
   std::vector<std::string> expected_input_methods;