Create the SystemUpdate activity class.

Test: tested sample app with sideloading.

Change-Id: I0d1661cea57c706b4981a4cda9f9b69fdeb69292
diff --git a/sample_updater/res/layout/activity_main.xml b/sample_updater/res/layout/activity_main.xml
new file mode 100644
index 0000000..bd7d686
--- /dev/null
+++ b/sample_updater/res/layout/activity_main.xml
@@ -0,0 +1,20 @@
+<!--
+  Copyright (C) 2018 The Android Open Source Project
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+  -->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+</LinearLayout>