Add logging for SettingsPanels

The 3 main categories are:
- Panel Opened
- Panel Closed
- Panel Slice interaction

There are 3 close events:
- See more button
- Done button
- Clicking outside the panel

Slice interactions will log the Uri of the Slice and the ActionType,
such as Toggle, Slider, Content (intent).

Change-Id: Iecad948f39f50dd12ae1bcb23a5d523e0df8bb98
Fixes: 117804231
Test: robotests

src/com/android/settings/panel/PanelLoggingContract.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2019 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.panel;
+
+/**
+ * Simple contract class to track keys in Panel logging.
+ *
+ * <p>
+ *    Constants should only be removed if underlying panel, or use case is removed.
+ * </p>
+ */
+public class PanelLoggingContract {
+
+    /**
+     * Keys tracking different ways users exit Panels.
+     */
+    interface PanelClosedKeys {
+        /**
+         * The user clicked the See More button linking deeper into Settings.
+         */
+        String KEY_SEE_MORE = "see_more";
+
+        /**
+         * The user clicked the Done button, closing the Panel.
+         */
+        String KEY_DONE = "done";
+
+        /**
+         * The user clicked outside the dialog, closing the Panel.
+         */
+        String KEY_CLICKED_OUT = "clicked_out";
+    }
+}