Time zone, Region, UTC picker

- Extract most common view related codes into BaseTimeZoneAdapter
  and BaseTimeZonePicker. Subclass handles the text formatting and
  order.
- Search view is added compared to previous version of time
  zone picker
- SpannableUtil is added to preserve spannable when formatting
  String resource.
- Fix the bug using GMT+<arabic> as time zone id. b/73132985
- Fix Talkback treating flags on screens as a separate element

Bug: 72146259
Bug: 73132985
Bug: 73952488
Test: mm RunSettingsRoboTests
Change-Id: I42c6ac369199c09d11e7f5cc4707358fa4780fed

res/menu/time_zone_base_search_menu.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2018 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.
+-->
+
+<menu xmlns:android="http://schemas.android.com/apk/res/android">
+    <item
+        android:id="@+id/time_zone_search_menu"
+        android:title="@string/search_settings"
+        android:icon="@*android:drawable/ic_search_api_material"
+        android:showAsAction="always|collapseActionView"
+        android:actionViewClass="android.widget.SearchView" />
+
+</menu>