Introduces CONTAINER_WIDGETS_TRAY to LauncherSettings.Favorites.

This would log LAUNCHER_ITEM_DRAG_STARTED event when an item is dragged from widgets tray. This also fixes empty component with widget logs.

Sample Log: https://docs.google.com/document/d/1CBP2yTcXdFhPdNG5ZmWFKSgd8mDbMevY-akVlUXPLDo/edit#bookmark=id.bk5w3n8uwhcl

Bug: 152978018
Change-Id: I51d16edae13973d5e62adda0e4efa861fa10dc1b
diff --git a/src/com/android/launcher3/LauncherSettings.java b/src/com/android/launcher3/LauncherSettings.java
index 87ead9e..535c9e6 100644
--- a/src/com/android/launcher3/LauncherSettings.java
+++ b/src/com/android/launcher3/LauncherSettings.java
@@ -153,12 +153,16 @@
         public static final int CONTAINER_PREDICTION = -102;
         public static final int CONTAINER_HOTSEAT_PREDICTION = -103;
         public static final int CONTAINER_ALL_APPS = -104;
+        public static final int CONTAINER_WIDGETS_TRAY = -105;
+
 
         public static final String containerToString(int container) {
             switch (container) {
                 case CONTAINER_DESKTOP: return "desktop";
                 case CONTAINER_HOTSEAT: return "hotseat";
                 case CONTAINER_PREDICTION: return "prediction";
+                case CONTAINER_ALL_APPS: return "all_apps";
+                case CONTAINER_WIDGETS_TRAY: return "widgets_tray";
                 default: return String.valueOf(container);
             }
         }