Delaying taskbar loading until user setup completed

> Also keeping it stashed while all-set activity is visible
> Creating a shared state (simiar to saved instance state) for taskbar
> Keeping taskbar stashed while all-set activity is visible

Bug: 194786060
Bug: 201782272
Test: Manual
Change-Id: Iab5e082243a206772266aece62d3028f5acb6400

quickstep/src/com/android/launcher3/taskbar/TaskbarSharedState.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2021 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.launcher3.taskbar;
+
+/**
+ * State shared across different taskbar instance
+ */
+public class TaskbarSharedState {
+
+    public int sysuiStateFlags;
+
+    public boolean setupUIVisible = false;
+
+}