Update Home settings nav bar color.

Updated the Hime settings nav bar color to match that of the wallpaper picker app.

Test: manual

fixes: 183396026
Change-Id: Id2302a553c5ddf645d497cb832608efecb3e70ad
diff --git a/res/values/styles.xml b/res/values/styles.xml
index a27cdac..fd77b80 100644
--- a/res/values/styles.xml
+++ b/res/values/styles.xml
@@ -150,7 +150,7 @@
     </style>
 
     <style name="HomeSettingsTheme" parent="@android:style/Theme.DeviceDefault.Settings">
-        <item name="android:navigationBarColor">@android:color/transparent</item>
+        <item name="android:navigationBarColor">?android:colorPrimaryDark</item>
         <item name="preferenceTheme">@style/HomeSettingsPreferenceTheme</item>
     </style>