Merge changes from topic "vm_permission_to_platform_app"

* changes:
  Sign demo app with the platform key
  Restrict MANAGE_VIRTUAL_MACHINE to platform signed apps
diff --git a/demo/Android.bp b/demo/Android.bp
index 77049de..37fc676 100644
--- a/demo/Android.bp
+++ b/demo/Android.bp
@@ -18,4 +18,5 @@
     platform_apis: true,
     use_embedded_native_libs: true,
     v4_signature: true,
+    certificate: "platform",
 }
diff --git a/javalib/AndroidManifest.xml b/javalib/AndroidManifest.xml
index 21857f8..f96b39f 100644
--- a/javalib/AndroidManifest.xml
+++ b/javalib/AndroidManifest.xml
@@ -18,7 +18,7 @@
   package="com.android.virtualmachine.res">
 
   <permission android:name="android.permission.MANAGE_VIRTUAL_MACHINE"
-      android:protectionLevel="normal" />
+      android:protectionLevel="signature" />
 
   <permission android:name="android.permission.DEBUG_VIRTUAL_MACHINE"
       android:protectionLevel="signature" />