Remove unused file res/layout/usb_dialog_container.xml

It looks like the class which used this (UsbModeChooserActivity.java)
was removed in 40bd570352.

Bug: 70848054
Test: should be covered by existing tests
Change-Id: I307852484055dc7f04dc81d5f03145dfde765add

res/layout/usb_dialog_container.xml

@@ -1,31 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-     Copyright (C) 2015 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.
--->
-
-<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:paddingTop="10dp"
-    android:paddingBottom="5dp">
-
-    <LinearLayout
-        android:id="@+id/container"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:paddingTop="20dp"
-        android:orientation="vertical" />
-
-</ScrollView>