Refine the banner view for accessibility features.

1. Replace the video with the gif for Magnification.
2. Replace the static image with the gif for Color Inversion.

Bug: 153293657
Bug: 155946967
Test: manual test & robo test
Change-Id: Ic51c0ec45c10a7fd2b9f1ffb63865ebc764846ba

res/layout/magnification_video_preference.xml

@@ -1,40 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright (C) 2016 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.
--->
-<RelativeLayout
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    android:layout_width="match_parent"
-    android:layout_height="wrap_content"
-    android:clipChildren="true"
-    android:clipToPadding="true">
-
-    <ImageView
-        android:id="@+id/video_background"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:src="@drawable/accessibility_screen_magnification_background"
-        android:scaleType="fitXY"
-        android:adjustViewBounds="true"
-        android:importantForAccessibility="noHideDescendants" />
-
-    <VideoView
-        android:id="@+id/video"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:layout_alignTop="@id/video_background"
-        android:layout_centerHorizontal="true"
-        android:importantForAccessibility="noHideDescendants" />
-
-</RelativeLayout>