Add dock_info_bottom_area_overlay

Add and overlay near keyguard_bottom_are to host the promo animation.

Bug: 182220090
Bug: 178998477
Test: atest SystemUITests:KeyguardBottomAreaTest
Test: atestSystemUITests:DockIndicationControllerTest
Change-Id: I93a3ddee3f4dc3273ba446dab6f9df49c262e955

packages/SystemUI/res/layout/dock_info_bottom_area_overlay.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ 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.
+  -->
+
+<!-- empty stub -->
+<merge />

packages/SystemUI/res/layout/status_bar_expanded.xml

@@ -101,6 +101,8 @@
 
     </com.android.systemui.statusbar.phone.NotificationsQuickSettingsContainer>
 
+    <include layout="@layout/dock_info_bottom_area_overlay" />
+
     <include
         layout="@layout/keyguard_bottom_area"
         android:visibility="gone" />

packages/SystemUI/src/com/android/systemui/statusbar/KeyguardIndicationController.java

@@ -492,8 +492,12 @@ public class KeyguardIndicationController implements KeyguardStateController.Cal
         return UserHandle.USER_NULL;
     }
 
-    @VisibleForTesting
-    protected void setVisible(boolean visible) {
+    /**
+     * Sets the visibility of keyguard bottom area, and if the indications are updatable.
+     *
+     * @param visible true to make the area visible and update the indication, false otherwise.
+     */
+    public void setVisible(boolean visible) {
         mVisible = visible;
         mIndicationArea.setVisibility(visible ? VISIBLE : GONE);
         if (visible) {