Remove unused widgets_scroll_container layout

Test: Compile NexusLauncher successfully

Bug: 181701011
Change-Id: I35d1c9324990e86496c45ca6db5f32f9588c7279

res/layout/widgets_scroll_container.xml

@@ -1,33 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright (C) 2017 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.
--->
-
-<HorizontalScrollView
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    android:id="@+id/widgets_scroll_container"
-    android:layout_width="match_parent"
-    android:layout_height="wrap_content"
-    android:background="?android:attr/colorPrimaryDark"
-    android:scrollbars="none">
-    <LinearLayout
-        android:id="@+id/widgets_cell_list"
-        style="@style/TextTitle"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:paddingStart="0dp"
-        android:paddingEnd="0dp"
-        android:orientation="horizontal"
-        android:showDividers="none"/>
-</HorizontalScrollView>