Turn off ExtensionWebRequestApiAuthRequiredTest.WebRequestAuthRequiredAsync

Test is flaky.

Bug: 1009570
Change-Id: I606f6be5e316cc1607f5773f3ea273628818bd52
TBR: karandeepb@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1832294Reviewed-by: Frank Liberato <liberato@chromium.org>
Commit-Queue: Frank Liberato <liberato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#701232}

chrome/browser/extensions/api/web_request/web_request_apitest.cc

@@ -542,7 +542,7 @@ IN_PROC_BROWSER_TEST_P(ExtensionWebRequestApiAuthRequiredTest,
 // Note: this is flaky on multiple platforms (crbug.com/1003598). Temporarily
 // enabled to find flakiness cause.
 IN_PROC_BROWSER_TEST_P(ExtensionWebRequestApiAuthRequiredTest,
-                       WebRequestAuthRequiredAsync) {
+                       DISABLED_WebRequestAuthRequiredAsync) {
   CancelLoginDialog login_dialog_helper;
 
   ASSERT_TRUE(StartEmbeddedTestServer());