Clean up theme part 1: move attrs to attrs.xml

And remove unused theme and layouts.

Bug: 111454230
Test: rebuild
Change-Id: Iaf418a9a3dc014fc0eac096e60b0e4581c6ededb

res/drawable/appwidget_item_bg.xml

@@ -1,23 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright (C) 2012 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.
--->
-
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-
-    <item android:state_pressed="true"
-          android:drawable="@drawable/appwidget_item_bg_pressed" />
-
-    <item android:drawable="@drawable/appwidget_item_bg_normal" />
-</selector>