Disable failing and flaky CTS tests

Disable WebViewClientTest testShouldOverrideUrlLoadingOnCreateWindow,
which has been flaky on L and N bot, and ServiceWorkerClientTest
testServiceWorkerClientInterceptCallback, which has been failing on N bot

BUG=659077, 675809

Review-Url: https://codereview.chromium.org/2590053002
Cr-Commit-Position: refs/heads/master@{#439840}

android_webview/tools/cts_config/expected_failure_on_bot.json

@@ -4,5 +4,17 @@
       "name": "testPageScroll",
       "_bug_id": "crbug.com/534643"
     }
+  ],
+  "android.webkit.cts.WebViewClientTest": [
+    {
+      "name": "testShouldOverrideUrlLoadingOnCreateWindow",
+      "_bug_id": "crbug.com/659077"
+    }
+  ],
+  "android.webkit.cts.ServiceWorkerClientTest": [
+    {
+      "name": "testServiceWorkerClientInterceptCallback",
+      "_bug_id": "crbug.com/675809"
+    }
   ]
 }