Change shortcut background to #FFFFFF, as per spec.

Bug: 28980830
Change-Id: Ie05ce97267cdeaebeb48691a948c61961d2a39d2
diff --git a/res/drawable/bg_white_pill.xml b/res/drawable/bg_white_pill.xml
index 186b06b..f92f739 100644
--- a/res/drawable/bg_white_pill.xml
+++ b/res/drawable/bg_white_pill.xml
@@ -16,6 +16,6 @@
 
 <shape xmlns:android="http://schemas.android.com/apk/res/android"
        android:shape="rectangle">
-    <solid android:color="@color/quantum_panel_bg_color" />
+    <solid android:color="#FFFFFF" />
     <corners android:radius="@dimen/bg_pill_radius" />
 </shape>
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