Add space around the data usage warning spinner.

Use a custom item layout for the data usage warning unit selection
spinner to make the touch target bigger.

Change-Id: I2d73dc3ab4c99cea8f8c791c8c1346240456d6aa
Fixes: 66414539
Test: visual

res/layout/data_usage_spinner_item.xml

@@ -0,0 +1,29 @@
+<?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.
+-->
+
+<!-- Copied from frameworks/base/core/res/res/layout/simple_spinner_item.xml and modified
+     layout height and added padding. -->
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+          android:id="@android:id/text1"
+          style="?android:attr/spinnerItemStyle"
+          android:singleLine="true"
+          android:layout_width="match_parent"
+          android:layout_height="?android:attr/listPreferredItemHeightSmall"
+          android:ellipsize="marquee"
+          android:textAlignment="inherit"
+          android:gravity="center"
+          android:paddingStart="30dp"
+          android:paddingEnd="30dp"/>

src/com/android/settings/datausage/BillingCycleSettings.java

@@ -264,7 +264,7 @@ public class BillingCycleSettings extends DataUsageBase implements
                 formatter.getUnitDisplayName(MeasureUnit.GIGABYTE)
             };
             final ArrayAdapter<String> adapter = new ArrayAdapter<String>(
-                    getContext(), android.R.layout.simple_spinner_item, unitNames);
+                    getContext(), R.layout.data_usage_spinner_item, unitNames);
             type.setAdapter(adapter);
 
             if (bytes > 1.5f * GB_IN_BYTES) {