Add CollapsingToolbarLayout for sub settings

Settings app is planning to make toolbar collapsible for next
Android release. This CL is to add a new layout for
CollapsingToolbarLayout in the Settings app and to update the theme
correspondly. This feature will be controlled by feature flag, which
makes Settings app compacitible with the existing layout.

Bug: 174451673
Test: manul test and visual verification
1) Enable the feature and open Settings app
2) Navigate to each sub page and check if toolbar is collapsible

Change-Id: Ibef524bbaa7ae3f0a43db7e40e599f42e009437f

res/layout/settings_collapsing_base_layout.xml

@@ -0,0 +1,64 @@
+<?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.
+-->
+<androidx.coordinatorlayout.widget.CoordinatorLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:id="@+id/content_parent"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <com.google.android.material.appbar.AppBarLayout
+        android:id="@+id/appbar_layout"
+        android:layout_width="match_parent"
+        android:layout_height="160dp"
+        android:theme="@style/Theme.CollapsingToolbar.Settings">
+
+        <com.google.android.material.appbar.CollapsingToolbarLayout
+            android:id="@+id/collapsing_toolbar"
+            android:background="?android:attr/colorPrimary"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            app:maxLines="3"
+            app:contentScrim="?android:attr/colorPrimary"
+            app:collapsedTitleTextAppearance="@style/ToolbarText.Collapsed"
+            app:statusBarScrim="?android:attr/colorPrimary"
+            app:layout_scrollFlags="scroll|exitUntilCollapsed"
+            app:toolbarId="@id/tool_bar">
+
+            <androidx.appcompat.widget.Toolbar
+                android:id="@+id/tool_bar"
+                android:layout_width="match_parent"
+                android:layout_height="?attr/actionBarSize"
+                app:layout_collapseMode="pin"
+                app:contentInsetStart="68dp"/>
+
+            <Toolbar
+                android:id="@+id/action_bar"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                app:layout_collapseMode="pin"
+                android:theme="?android:attr/actionBarTheme"/>
+
+        </com.google.android.material.appbar.CollapsingToolbarLayout>
+    </com.google.android.material.appbar.AppBarLayout>
+
+    <FrameLayout
+        android:id="@+id/content_frame"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
+</androidx.coordinatorlayout.widget.CoordinatorLayout>

res/values-night/themes.xml

@@ -44,4 +44,10 @@
     <style name="Theme.TabTheme" parent="@style/Theme.MaterialComponents.DayNight">
         <item name="colorPrimary">@*android:color/edge_effect_device_default_dark</item>
     </style>
+
+    <style name="Theme.CollapsingToolbar.Settings"
+           parent="@style/Theme.MaterialComponents.DayNight">
+        <item name="colorPrimary">@*android:color/primary_dark_device_default_settings</item>
+        <item name="colorAccent">@*android:color/accent_device_default_dark</item>
+    </style>
 </resources>

res/values/styles.xml

@@ -874,4 +874,17 @@
         <item name="android:textSize">16sp</item>
         <item name="android:textColor">?android:attr/textColorSecondary</item>
     </style>
+
+    <style name="ToolbarText.Collapsed"
+           parent="@android:style/TextAppearance.DeviceDefault.Widget.ActionBar.Title">
+    </style>
+
+    <style name="ToolbarText"
+           parent="@android:style/TextAppearance.DeviceDefault.Widget.ActionBar.Title" >
+        <item name="android:textSize">32sp</item>
+    </style>
+
+    <style name="ToolbarText.MoreThanTwoLines">
+        <item name="android:textSize">24sp</item>
+    </style>
 </resources>

res/values/themes.xml

@@ -72,7 +72,7 @@
         <item name="android:windowNoTitle">true</item>
     </style>
 
-    <style name="Theme.SubSettings.Base" parent="Theme.Settings">
+    <style name="Theme.SubSettings.Base" parent="Theme.Settings.NoActionBar">
         <!-- Redefine the ActionBar style for contentInsetStart -->
         <item name="android:actionBarStyle">@style/Widget.ActionBar.SubSettings</item>
 
@@ -276,4 +276,10 @@
     <style name="Theme.TabTheme" parent="@style/Theme.MaterialComponents.DayNight">
         <item name="colorPrimary">@*android:color/edge_effect_device_default_light</item>
     </style>
+
+    <style name="Theme.CollapsingToolbar.Settings"
+           parent="@style/Theme.MaterialComponents.DayNight">
+        <item name="colorPrimary">@*android:color/primary_device_default_settings_light</item>
+        <item name="colorAccent">@*android:color/accent_device_default_light</item>
+    </style>
 </resources>