Refines animation for caption preferences tutorial

- Avoid the banner asset making confusing end user why the asset cannot play.

Bug: 153683816
Bug: 148837311
Test: loca test
Change-Id: I47980490f6913711c4af063a07b80347a08297a2

res/layout/accessibility_captions_preview.xml

@@ -1,18 +1,18 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!--
-  ~ Copyright (C) 2020 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.
+  Copyright (C) 2020 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