Disable failing tests on WebView bots

android_webview/tools/cts_config/expected_failure_on_bot.json

 {
   "android.webkit.cts.WebViewTest": [
     {
       "name": "testPageScroll",
       "_bug_id": "crbug.com/534643"
     },
     {
       "name": "testJavascriptInterfaceForClientPopup",
       "_bug_id": "crbug.com/698369"
     }
   ],
   "android.webkit.cts.WebSettingsTest": [
     {
       "name": "testLocalImageLoads",
       "_bug_id": "crbug.com/680759"
     }
   ],
   "android.webkit.cts.WebViewClientTest": [
     {
       "name": "testShouldOverrideUrlLoadingOnCreateWindow",
       "_bug_id": "crbug.com/659077"
     }
   ],
+  "android.webkit.cts.WebChromeClientTest": [
+    {
+      "name": "testWebViewIncludedStableInterfaces",
+      "_bug_id": "crbug.com/719974"
+    }
+  ],
   "android.webkit.cts.ServiceWorkerClientTest": [
     {
       "name": "testServiceWorkerClientInterceptCallback",
       "_bug_id": "crbug.com/675809"
     }
   ]
 }