Removing additional rpc due to icon cache update

When launcher loads, it fetches the list of apps twice, once for
loading all-apps and again for updating icons. Instead reusing
the previously fetched apps list.
Also moving the icon loading in a separate package for further
generalization

Change-Id: Ibd2dae56e6027a31b633da030bc6b43a90b27e1b
diff --git a/src/com/android/launcher3/LauncherModel.java b/src/com/android/launcher3/LauncherModel.java
index 7a90a55..df1c693 100644
--- a/src/com/android/launcher3/LauncherModel.java
+++ b/src/com/android/launcher3/LauncherModel.java
@@ -39,6 +39,7 @@
 import com.android.launcher3.compat.PackageInstallerCompat.PackageInstallInfo;
 import com.android.launcher3.compat.UserManagerCompat;
 import com.android.launcher3.graphics.LauncherIcons;
+import com.android.launcher3.icons.IconCache;
 import com.android.launcher3.model.AddWorkspaceItemsTask;
 import com.android.launcher3.model.BaseModelUpdateTask;
 import com.android.launcher3.model.BgDataModel;