Update Backup & reset settings to launch the configured activity.

Check for configured backup settings activity to be used for
Settings->Backup & reset.

Bug: 28942163
Change-Id: I8b937fde5b400afdb81463c9c278b3e3ad42688b

src/com/android/settings/BackupSettingsActivity.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2016 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.settings;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.os.Bundle;
+import android.text.TextUtils;
+import android.util.Log;
+
+import com.android.settings.R;
+
+import java.net.URISyntaxException;
+
+/**
+ * A trampoline activity used to launch the configured Backup activity.
+ * This activity used the theme NoDisplay to minimize the flicker that might be seen for the launch-
+ * finsih transition.
+ */
+public class BackupSettingsActivity extends Activity {
+    private static final String TAG = "BackupSettingsActivity";
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        String backup = getResources().getString(R.string.config_backup_settings_intent);
+        if (!TextUtils.isEmpty(backup)) {
+            try {
+                Intent intent = Intent.parseUri(backup, 0);
+                if (intent.resolveActivity(getPackageManager()) != null) {
+                    // use startActivityForResult to let the activity check the caller signature
+                    startActivityForResult(intent, -1);
+                } else {
+                    Log.e(TAG, "Backup component not found!");
+                }
+            } catch (URISyntaxException e) {
+                Log.e(TAG, "Invalid backup component URI!", e);
+            }
+        }
+        finish();
+    }
+}