Remove references to SettingsBase styles

We've moved the values for several preference-related styles used in
Settings from SettingsLib into the support library. This CL removes the
references to the SettingsLib versions from Settings so they can be
removed from SettingsLib.

Also delete an unused layout file that was moved to SettingsLib a long
time ago (preference_dropdown_material_settings.xml).

Bug: 64689839
Test: visual (styles for things like icon spacing, dividers, etc. should
be the same)

Change-Id: Ib7a745218086269c2e861b18df68bd835929da19

res/layout/preference_dropdown_material_settings.xml

@@ -1,35 +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.
-  -->
-
-
-<!-- Based off frameworks/base/core/res/res/layout/preference_dropdown_material.xml
-     except that icon space in this layout is always reserved -->
-<FrameLayout
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    android:layout_width="match_parent"
-    android:layout_height="wrap_content">
-
-    <Spinner
-        android:id="@+id/spinner"
-        android:layout_width="0dp"
-        android:layout_height="wrap_content"
-        android:layout_marginStart="@dimen/preference_no_icon_padding_start"
-        android:visibility="invisible" />
-
-    <include layout="@layout/preference_material"/>
-
-</FrameLayout>

res/values/styles_preference.xml

@@ -20,27 +20,27 @@
 <resources>
 
     <!-- Fragment style -->
-    <style name="SettingsPreferenceFragmentStyle" parent="@style/PreferenceFragmentStyle.SettingsBase">
+    <style name="SettingsPreferenceFragmentStyle" parent="@style/PreferenceFragment.Material">
         <item name="android:layout">@layout/preference_list_fragment</item>
     </style>
 
-    <style name="ApnPreference" parent="Preference.SettingsBase">
+    <style name="ApnPreference" parent="@style/Preference.Material">
         <item name="android:layout">@layout/apn_preference_layout</item>
     </style>
 
-    <style name="SettingsSeekBarPreference" parent="Preference.SettingsBase">
+    <style name="SettingsSeekBarPreference" parent="@style/Preference.Material">
         <item name="android:layout">@layout/preference_widget_seekbar_settings</item>
     </style>
 
-    <style name="SyncSwitchPreference" parent="Preference.SettingsBase">
+    <style name="SyncSwitchPreference" parent="@style/Preference.Material">
         <item name="android:widgetLayout">@layout/preference_widget_sync_toggle</item>
     </style>
 
-    <style name="TwoStateButtonPreference" parent="Preference.SettingsBase">
+    <style name="TwoStateButtonPreference" parent="@style/Preference.Material">
         <item name="android:layout">@layout/two_state_button</item>
     </style>
 
-    <style name="SettingsMultiSelectListPreference" parent="Preference.SettingsBase">
+    <style name="SettingsMultiSelectListPreference" parent="@style/Preference.Material">
         <item name="android:positiveButtonText">@android:string/ok</item>
         <item name="android:negativeButtonText">@android:string/cancel</item>
     </style>