ExactCalculator: Remove all elevation shadows

History page reverse shadow looks bad.
Bottom rounded corner shadow gets clipped when using
3 button navigation. Let's just remove all elevations.

Change-Id: I73d737006dafc4fc9e1d75ab747fcf8f541b1c50
diff --git a/res/layout/display_one_line.xml b/res/layout/display_one_line.xml
index e5a83b3..dbe6e08 100644
--- a/res/layout/display_one_line.xml
+++ b/res/layout/display_one_line.xml
@@ -22,7 +22,6 @@
     android:layout_height="match_parent"
     android:background="@drawable/rounded_bottom"
     android:clipChildren="false"
-    android:elevation="4dip"
     android:orientation="vertical">
 
     <include layout="@layout/toolbar" />
diff --git a/res/layout/display_two_line.xml b/res/layout/display_two_line.xml
index 1b36799..1599df3 100644
--- a/res/layout/display_two_line.xml
+++ b/res/layout/display_two_line.xml
@@ -21,7 +21,6 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:background="@drawable/rounded_bottom"
-    android:elevation="4dip"
     android:orientation="vertical">
 
     <include layout="@layout/toolbar" />
diff --git a/res/layout/fragment_history.xml b/res/layout/fragment_history.xml
index 2bc2d7a..d2c294a 100644
--- a/res/layout/fragment_history.xml
+++ b/res/layout/fragment_history.xml
@@ -26,7 +26,6 @@
         android:id="@+id/history_toolbar"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:elevation="4dip"
         android:minHeight="?attr/actionBarSize"
         android:navigationContentDescription="@string/desc_navigate_up"
         app:navigationIcon="?attr/homeAsUpIndicator"