Tweak grid item layout.  Adjust colors to match spec.

BUG=10960718
BUG=24326989

Change-Id: I74da23fe0b40d713a3f435d1467d26d707e76fca
diff --git a/res/values/styles.xml b/res/values/styles.xml
index 15d17cc..6712e2d 100644
--- a/res/values/styles.xml
+++ b/res/values/styles.xml
@@ -25,6 +25,7 @@
         <item name="actionBarTheme">@style/ActionBarTheme</item>
         <item name="actionBarPopupTheme">@style/ActionBarPopupTheme</item>
 
+        <item name="android:windowBackground">@color/window_background</item>
         <item name="android:colorPrimaryDark">@color/primary_dark</item>
         <item name="android:colorPrimary">@color/primary</item>
         <item name="android:colorAccent">@color/accent</item>
@@ -44,6 +45,7 @@
         <item name="actionBarTheme">@style/ActionBarTheme</item>
         <item name="actionBarPopupTheme">@style/ActionBarPopupTheme</item>
 
+        <item name="android:windowBackground">@color/window_background</item>
         <item name="android:colorPrimaryDark">@color/primary_dark</item>
         <item name="android:colorPrimary">@color/primary</item>
         <item name="android:colorAccent">@color/accent</item>