Add basic HistoryFragment

Bug: 31623549
Test: Manually verified history fragment can be added / removed.
Change-Id: Ib3ae8d976811f057d9b99dd503abcaa47ac92ae7
diff --git a/res/layout/activity_calculator_port.xml b/res/layout/activity_calculator_port.xml
index 4cafa94..30aaf00 100644
--- a/res/layout/activity_calculator_port.xml
+++ b/res/layout/activity_calculator_port.xml
@@ -21,7 +21,7 @@
     android:layout_height="match_parent"
     android:orientation="vertical">
 
-    <include layout="@layout/display"/>
+    <include layout="@layout/display" />
 
     <com.android.calculator2.CalculatorPadViewPager
         android:id="@+id/pad_pager"