Fix UsageBar for Storage Settings

- make padding consistent with the rest of the Settings App

See bug: #15384992 Setting Dashboard - padding updates

Change-Id: Id333493cc4e88355a1211834081cd22e61aabf77
diff --git a/res/layout/preference_memoryusage.xml b/res/layout/preference_memoryusage.xml
index ddc619d..609ae3a 100644
--- a/res/layout/preference_memoryusage.xml
+++ b/res/layout/preference_memoryusage.xml
@@ -20,8 +20,8 @@
     android:layout_height="wrap_content"
     android:minHeight="?android:attr/listPreferredItemHeight"
     android:gravity="center_vertical"
-    android:paddingEnd="?android:attr/scrollbarSize"
-    android:paddingStart="@*android:dimen/preference_widget_width">
+    android:paddingStart="?android:attr/listPreferredItemPaddingStart"
+    android:paddingEnd="?android:attr/listPreferredItemPaddingEnd">
 
     <com.android.settings.deviceinfo.PercentageBarChart
         android:id="@+id/percentage_bar_chart"