Fix path for handling system window with app token.

It is wrong to turn the token into a null appWindowToken; we
need to create a new top-level token as if they had passed in null.

Change-Id: I870d8167c6ed456ea8fd58b149809ec9e0103bce
diff --git a/tests/ActivityTests/AndroidManifest.xml b/tests/ActivityTests/AndroidManifest.xml
index 15d075c..c0898d30 100644
--- a/tests/ActivityTests/AndroidManifest.xml
+++ b/tests/ActivityTests/AndroidManifest.xml
@@ -23,6 +23,7 @@
     <uses-permission android:name="android.permission.INTERACT_ACROSS_USERS" />
     <uses-permission android:name="android.permission.INTERACT_ACROSS_USERS_FULL" />
     <uses-permission android:name="android.permission.MANAGE_USERS" />
+    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
     <application android:label="ActivityTest">
         <activity android:name="ActivityTestMain">
             <intent-filter>