[WebViewShell] Add activity for opening urls while creating/destroying webviews.

android_webview/tools/system_webview_shell/apk/AndroidManifest.xml

 <!--
  * Copyright 2015 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
 -->
 
 <manifest
     xmlns:android="http://schemas.android.com/apk/res/android"
     package="org.chromium.webview_shell"
     android:versionCode="1"
@@ skipping 40 matching lines @@
             android:noHistory="true"
             android:exported="true">
         </activity>
         <activity
             android:name="org.chromium.webview_shell.StartupTimeActivity"
             android:label="@string/title_activity_startup_time"
             android:noHistory="true"
             android:exported="true">
         </activity>
         <activity
+            android:name="org.chromium.webview_shell.WebViewCreateDestroyActivity"
+            android:launchMode="singleTask"
+            android:label="@string/title_activity_create_destroy"
+            android:exported="true">
+        </activity>
+        <activity
             android:name="org.chromium.webview_shell.WebViewBrowserActivity"
             android:label="@string/title_activity_browser"
             android:exported="true"
             android:windowSoftInputMode="adjustResize"
             android:configChanges="orientation|screenSize|smallestScreenSize|screenLayout">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
             <!-- Catch intents which do not specify a MIME type -->
@@ skipping 32 matching lines @@
 
         <activity
             android:name="org.chromium.webview_shell.PageCyclerTestActivity"
             android:label="@string/title_activity_page_cycler"
             android:exported="true">
         </activity>
 
         <uses-library android:name="android.test.runner" />
     </application>
 </manifest>