Added feature for surveys provider to Settings

It is now possible to create and show surveys to a user
asking them for feedback within the Settings app.

Test: JUnitTests
Bug: 27823357
Change-Id: I824899045f6ce30e5b6f46d20888da673114f658

src/com/android/settings/overlay/SurveyFeatureProvider.java

@@ -0,0 +1,55 @@
+/*
+ * 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.overlay;
+
+import android.app.Activity;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.IntentFilter;
+import android.support.annotation.Nullable;
+
+/**
+ * An interface for classes wishing to provide the ability to serve surveys to implement.
+ */
+public interface SurveyFeatureProvider {
+
+    /**
+     * Downloads a survey asynchronously to shared preferences to be served at a later date.
+     *
+     * @param activity A valid context.
+     * @param surveyId A unique Id representing a survey to download.
+     * @param data a text blob to be attached to the survey results.
+     */
+    void downloadSurvey(Activity activity, String surveyId, @Nullable String data);
+
+    /**
+     * Shows a previously downloaded survey/prompt if possible in the activity provided.
+     *
+     * @param activity The host activity to show the survey in.
+     * @param surveyId A unique Id representing a survey to download.
+     */
+    void showSurveyIfAvailable(Activity activity, String surveyId);
+
+    /**
+     * A helper method to get the surveyId. Implementers should create a mapping of
+     * keys to surveyIds and provide them via this function.
+     *
+     * @param context A valid context.
+     * @param key The key to get the surveyId for.
+     * @return The unique Id as a string or null on error.
+     */
+    String getSurveyId(Context context, String key);
+}