Merge changes I135e5218,I1efd9760,Ia3d03054,I1fbe3157,Ic206a940, ...

* changes:
  Add seekBar properties 'tickMark' to LabeledSeekBarPreference
  Add the preference controller to control accessibility button fade preference
  Add the preference controller to control accessibility button preview preference
  Add the preference controller to control accessibility button opacity preference
  Add the preference controller to control accessibility button size preference
  Add the preference controller to control accessibility button location preference
  Setup basic layout and resources for the accessibility button settings page

res/layout/accessibility_button_preview.xml

@@ -0,0 +1,33 @@
+<?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.
+-->
+
+<FrameLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:clipToPadding="false"
+    android:importantForAccessibility="noHideDescendants">
+
+    <ImageView
+        android:id="@+id/preview_image"
+        android:layout_width="match_parent"
+        android:layout_height="@dimen/accessibility_button_preview_height"
+        android:layout_gravity="center"
+        android:scaleType="fitCenter"
+        android:focusable="false"
+        android:clickable="false"
+        android:adjustViewBounds="true"/>
+</FrameLayout>