Add IconCache support for deep shortcuts, loads deepshortcut on

background thread.  Added a feature flag to toggle on/off this
feature.

Bug: 140242324
Test:
  1. (Custom Shortcut) Long click on google maps -> widgets -> drag
     driving mode to workspace.

  2. Open chrome -> add to home screen -> add -> add automatically.

  3. InstallShortcutReceiver
     In Launcher.completeAddShortcut, commend out the code that
     calls PinRequestHelper.createWorkspaceItemFromPinItemRequest,
     then open chrome -> add to home screen -> add -> add
     automatically.

  4. ShortcutDragPreviewProvider
     qdb -> long press on suggested app that has deep shortcut
     -> drag to workspace.

Change-Id: If7babe4eddf5434909bf686b4e9bde15e444d9fd

iconloaderlib/src/com/android/launcher3/icons/cache/IconCacheUpdateHandler.java

@@ -171,7 +171,8 @@ public class IconCacheUpdateHandler {
                 long updateTime = c.getLong(indexLastUpdate);
                 int version = c.getInt(indexVersion);
                 T app = componentMap.remove(component);
-                if (version == info.versionCode && updateTime == info.lastUpdateTime
+                if (version == info.versionCode
+                        && updateTime == cachingLogic.getLastUpdatedTime(app, info)
                         && TextUtils.equals(c.getString(systemStateIndex),
                                 mIconCache.getIconSystemState(info.packageName))) {
 
@@ -231,7 +232,6 @@ public class IconCacheUpdateHandler {
         }
     }
 
-
     /**
      * A runnable that updates invalid icons and adds missing icons in the DB for the provided
      * LauncherActivityInfo list. Items are updated/added one at a time, so that the