Make background of spinner become white color

If background is transparent, user will see the content
under this widget. So change it to white color.

Test: visual
Bug: 121148001
Change-Id: I1b10c83e9bc68e95c1d9720c62feb31fb7ab7e2b
diff --git a/packages/SettingsLib/SettingsSpinner/res/drawable/settings_spinner_background.xml b/packages/SettingsLib/SettingsSpinner/res/drawable/settings_spinner_background.xml
index cbebbb3..d6dc211 100644
--- a/packages/SettingsLib/SettingsSpinner/res/drawable/settings_spinner_background.xml
+++ b/packages/SettingsLib/SettingsSpinner/res/drawable/settings_spinner_background.xml
@@ -18,12 +18,11 @@
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android"
             android:paddingMode="stack">
     <item>
-        <shape
-            android:tint="?android:attr/colorForeground">
+        <shape>
             <corners
                 android:radius="20dp"/>
             <solid
-                android:color="@android:color/transparent"/>
+                android:color="?android:attr/colorPrimary"/>
             <stroke
                 android:color="#1f000000"
                 android:width="1dp"/>