Create the SystemUpdate activity class.

Test: tested sample app with sideloading.

Change-Id: I0d1661cea57c706b4981a4cda9f9b69fdeb69292
diff --git a/sample_updater/src/com/android/update/ui/SystemUpdateActivity.java b/sample_updater/src/com/android/update/ui/SystemUpdateActivity.java
new file mode 100644
index 0000000..e57b167
--- /dev/null
+++ b/sample_updater/src/com/android/update/ui/SystemUpdateActivity.java
@@ -0,0 +1,68 @@
+/*
+ * 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.
+ */
+
+package com.android.update.ui;
+
+import android.app.Activity;
+import android.os.UpdateEngine;
+import android.os.UpdateEngineCallback;
+
+/** Main update activity. */
+public class SystemUpdateActivity extends Activity {
+
+  private UpdateEngine updateEngine;
+  private UpdateEngineCallbackImpl updateEngineCallbackImpl = new UpdateEngineCallbackImpl(this);
+
+  @Override
+  public void onResume() {
+    super.onResume();
+    updateEngine = new UpdateEngine();
+    updateEngine.bind(updateEngineCallbackImpl);
+  }
+
+  @Override
+  public void onPause() {
+    updateEngine.unbind();
+    super.onPause();
+  }
+
+  void onStatusUpdate(int i, float v) {
+    // Handle update engine status update
+  }
+
+  void onPayloadApplicationComplete(int i) {
+    // Handle apply payload completion
+  }
+
+  private static class UpdateEngineCallbackImpl extends UpdateEngineCallback {
+
+    private final SystemUpdateActivity activity;
+
+    public UpdateEngineCallbackImpl(SystemUpdateActivity activity) {
+      this.activity = activity;
+    }
+
+    @Override
+    public void onStatusUpdate(int i, float v) {
+      activity.onStatusUpdate(i, v);
+    }
+
+    @Override
+    public void onPayloadApplicationComplete(int i) {
+      activity.onPayloadApplicationComplete(i);
+    }
+  }
+}